diff --git a/src/Bundle/ChillTaskBundle/Controller/SingleTaskController.php b/src/Bundle/ChillTaskBundle/Controller/SingleTaskController.php
index 359dc8909..b11601589 100644
--- a/src/Bundle/ChillTaskBundle/Controller/SingleTaskController.php
+++ b/src/Bundle/ChillTaskBundle/Controller/SingleTaskController.php
@@ -160,13 +160,17 @@ final class SingleTaskController extends AbstractController
 
                 $this->addFlash('success', $this->translator->trans("The task is created"));
 
+                if ($request->query->has('returnPath')) {
+                    return $this->redirect($request->query->get('returnPath'));
+                }
+
                 if ($entityType === 'person') {
                     return $this->redirectToRoute('chill_task_singletask_list', [
                         'person_id' => $task->getPerson()->getId()
                     ]);
                 } elseif ($entityType === 'course') {
-                    return $this->redirectToRoute('chill_task_singletask_courselist', [
-                        'course_id' => $task->getCourse()->getId()
+                    return $this->redirectToRoute('chill_task_singletask_by-course_list', [
+                        'id' => $task->getCourse()->getId()
                     ]);
                 }
             } else {
@@ -179,13 +183,13 @@ final class SingleTaskController extends AbstractController
                 return $this->render('@ChillTask/SingleTask/Person/new.html.twig', array(
                 'form' => $form->createView(),
                 'task' => $task,
-                'person' => $person,
+                'person' => $task->getPerson(),
             ));
             case 'course':
                 return $this->render('@ChillTask/SingleTask/AccompanyingCourse/new.html.twig', array(
                 'form' => $form->createView(),
                 'task' => $task,
-                'accompanyingCourse' => $course,
+                'accompanyingCourse' => $task->getCourse(),
             ));
             default:
                 throw new \LogicException("entity context not supported");
@@ -198,68 +202,23 @@ final class SingleTaskController extends AbstractController
      * name="chill_task_single_task_show"
      * )
      */
-    public function showAction($id, Request $request)
+    public function showAction(SingleTask $task, Request $request)
     {
+        $this->denyAccessUnlessGranted(TaskVoter::SHOW, $task);
 
-        $em = $this->getDoctrine()->getManager();
-        $task = $em->getRepository(SingleTask::class)->find($id);
-
-        if (!$task) {
-            throw $this->createNotFoundException('Unable to find Task entity.');
-        }
-
-        if ($task->getPerson() !== null) {
-
-            $personId = $task->getPerson()->getId();
-
-            if ($personId === null) {
-                return new Response("You must provide a person_id", Response::HTTP_BAD_REQUEST);
-            }
-
-            $person = $this->getDoctrine()->getManager()
-                ->getRepository(Person::class)
-                ->find($personId);
-
-            if ($person === null) {
-                throw $this->createNotFoundException("Invalid person id");
-            }
-
+        if ($person = $task->getContext() instanceof Person) {
             $event = new PrivacyEvent($person, array(
-            'element_class' => SingleTask::class,
-            'element_id' => $task->getId(),
-            'action' => 'show'
+                'element_class' => SingleTask::class,
+                'element_id' => $task->getId(),
+                'action' => 'show'
             ));
             $this->eventDispatcher->dispatch(PrivacyEvent::PERSON_PRIVACY_EVENT, $event);
-
         }
 
-        if ($task->getCourse() !== null)
-        {
-            $courseId = $task->getCourse()->getId();
-
-            if ($courseId === null) {
-                return new Response("You must provide a course_id", Response::HTTP_BAD_REQUEST);
-            }
-
-            $course = $this->getDoctrine()->getManager()
-            ->getRepository(AccompanyingPeriod::class)
-            ->find($courseId);
-
-            if ($course === null)
-            {
-                throw $this->createNotFoundException("Invalid course id");
-            }
-        }
-
-
-        $this->denyAccessUnlessGranted(TaskVoter::SHOW, $task, 'You are not '
-            . 'allowed to view this task');
-
         $timeline = $this->timelineBuilder
             ->getTimelineHTML('task', array('task' => $task));
 
-
-        if($task->getContext() instanceof Person){
+        if ($task->getContext() instanceof Person) {
             return $this->render('@ChillTask/SingleTask/Person/show.html.twig', array(
                 'task'      => $task,
                 'timeline'  => $timeline
@@ -281,52 +240,16 @@ final class SingleTaskController extends AbstractController
      * )
      */
     public function editAction(
-        $id,
+        SingleTask $task,
         Request $request
     ) {
 
-        $em = $this->getDoctrine()->getManager();
-        $task = $em->getRepository(SingleTask::class)->find($id);
-
-        if ($task->getContext() instanceof Person) {
-            $personId = $task->getPerson()->getId();
-            if ($personId === null) {
-                return new Response("You must provide a person_id", Response::HTTP_BAD_REQUEST);
-            }
-
-            $person = $this->getDoctrine()->getManager()
-                ->getRepository(Person::class)
-                ->find($personId);
-
-            if ($person === null) {
-                throw $this->createNotFoundException("Invalid person id");
-            }
-        } else {
-            $courseId = $task->getCourse()->getId();
-            if ($courseId === null) {
-                return new Response("You must provide a course_id", Response::HTTP_BAD_REQUEST);
-            }
-
-            $course = $this->getDoctrine()->getManager()
-                ->getRepository(AccompanyingPeriod::class)
-                ->find($courseId);
-
-            if ($course === null) {
-                throw $this->createNotFoundException("Invalid accompanying period id");
-            }
-        }
-
         $this->denyAccessUnlessGranted(TaskVoter::UPDATE, $task, 'You are not '
             . 'allowed to edit this task');
 
-        if (!$task) {
-            throw $this->createNotFoundException('Unable to find Task entity.');
-        }
-
         $event = (new UIEvent('single-task', $task))
             ->setForm($this->setCreateForm($task, new Role(TaskVoter::UPDATE)))
             ;
-
         $this->eventDispatcher->dispatch(UIEvent::EDIT_FORM, $event);
 
         $form = $event->getForm();
@@ -343,7 +266,7 @@ final class SingleTaskController extends AbstractController
                 $this->addFlash('success', $this->translator
                     ->trans("The task has been updated"));
 
-                if($task->getContext() instanceof Person){
+                if ($person = $task->getContext() instanceof Person) {
                     $event = new PrivacyEvent($person, array(
                     'element_class' => SingleTask::class,
                     'element_id' => $task->getId(),
@@ -351,14 +274,20 @@ final class SingleTaskController extends AbstractController
                     ));
                     $this->eventDispatcher->dispatch(PrivacyEvent::PERSON_PRIVACY_EVENT, $event);
 
+                    if ($request->query->has('returnPath')) {
+                        return $this->redirect($request->query->get('returnPath'));
+                    }
+
                     return $this->redirectToRoute(
                         'chill_task_singletask_list',
-                        $request->query->get('list_params', [])
                     );
                 } else {
+                    if ($request->query->has('returnPath')) {
+                        return $this->redirect($request->query->get('returnPath'));
+                    }
+
                     return $this->redirectToRoute(
-                        'chill_task_singletask_courselist',
-                        $request->query->get('list_params', [])
+                        'chill_task_singletask_by-course_list', ['id' => $task->getCourse()->getId()]
                     );
                 }
             } else {
@@ -372,7 +301,7 @@ final class SingleTaskController extends AbstractController
             return $event->getResponse();
         }
 
-        if($task->getContext() instanceof Person){
+        if ($person = $task->getContext() instanceof Person) {
             $event = new PrivacyEvent($person, array(
                 'element_class' => SingleTask::class,
                 'element_id' => $task->getId(),
@@ -388,7 +317,7 @@ final class SingleTaskController extends AbstractController
             return $this->render('@ChillTask/SingleTask/AccompanyingCourse/edit.html.twig', array(
                 'task'      => $task,
                 'form'      => $form->createView(),
-                'accompanyingCourse' => $course
+                'accompanyingCourse' => $task->getCourse()
             ));
         }
 
@@ -478,10 +407,9 @@ final class SingleTaskController extends AbstractController
                     ])));
                 } else {
                     return $this->redirect($this->generateUrl(
-                    'chill_task_singletask_courselist',
-                    $request->query->get('list_params', [
-                        'course_id' => $course->getId()
-                    ])));
+                    'chill_task_singletask_by-course_list',
+                        ['id' => $course->getId()]
+                    ));
                 }
             }
         }
@@ -510,7 +438,6 @@ final class SingleTaskController extends AbstractController
     protected function setCreateForm(SingleTask $task, Role $role)
     {
         $form = $this->createForm(SingleTaskType::class, $task, [
-            'center' => $this->centerResolverDispatcher->resolveCenter($task),
             'role'   => $role,
         ]);
 
@@ -817,39 +744,24 @@ final class SingleTaskController extends AbstractController
 
     /**
      * @Route(
-     *  "/{_locale}/task/single-task/courselist",
-     *  name="chill_task_singletask_courselist")
+     *  "/{_locale}/task/single-task/by-course/{id}",
+     *  name="chill_task_singletask_by-course_list")
      */
 
     public function listCourseTasks(
-        AccompanyingPeriodRepository $courseRepository,
+        AccompanyingPeriod $course,
         SingleTaskRepository $taskRepository,
         FormFactoryInterface $formFactory,
         Request $request
         ): Response
     {
 
-        if (!empty($request->query->get('course_id', NULL))) {
-
-            $courseId = $request->query->getInt('course_id', 0);
-            $course = $courseRepository->find($courseId);
-
-            if ($course === null) {
-                 throw $this->createNotFoundException("This accompanying course ' $courseId ' does not exist.");
-            }
-
-        }
-
         $em = $this->getDoctrine()->getManager();
 
-        if($course === NULL) {
-            throw $this->createNotFoundException('Accompanying course not found');
-        }
-
         $tasks = $taskRepository
-        ->findBy(
-            array('course' => $course)
-        );
+            ->findBy(
+                array('course' => $course)
+            );
 
         $form = $formFactory->createNamed(null, SingleTaskListType::class, null, [
                 'accompanyingCourse' => $course,
diff --git a/src/Bundle/ChillTaskBundle/Entity/AbstractTask.php b/src/Bundle/ChillTaskBundle/Entity/AbstractTask.php
index b3f0c6a9f..d34a0b05f 100644
--- a/src/Bundle/ChillTaskBundle/Entity/AbstractTask.php
+++ b/src/Bundle/ChillTaskBundle/Entity/AbstractTask.php
@@ -253,11 +253,6 @@ abstract class AbstractTask implements HasScopeInterface, HasCenterInterface
 
     public function getContext()
     {
-        // if ($this->getCourse() instanceof AccompanyingPeriod){
-        //     return $this->getCourse();
-        // } else {
-        //     return $this->getPerson();
-        // }
         return $this->getPerson() ?? $this->getCourse();
     }
 
diff --git a/src/Bundle/ChillTaskBundle/Form/SingleTaskType.php b/src/Bundle/ChillTaskBundle/Form/SingleTaskType.php
index 7fbc84800..a3dd1777f 100644
--- a/src/Bundle/ChillTaskBundle/Form/SingleTaskType.php
+++ b/src/Bundle/ChillTaskBundle/Form/SingleTaskType.php
@@ -19,6 +19,7 @@ namespace Chill\TaskBundle\Form;
 
 use Chill\MainBundle\Security\Resolver\CenterResolverDispatcher;
 use Chill\MainBundle\Security\Resolver\ScopeResolverDispatcher;
+use Chill\TaskBundle\Security\Authorization\TaskVoter;
 use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface;
 use Symfony\Component\Form\AbstractType;
 use Symfony\Component\Form\FormBuilderInterface;
@@ -60,7 +61,7 @@ class SingleTaskType extends AbstractType
             ->add('assignee', UserPickerType::class, [
                 'required' => false,
                 'center' => $center,
-                'role'   => $options['role'],
+                'role'   => TaskVoter::SHOW,
                 'placeholder' => 'Not assigned'
                 ])
             ->add('startDate', ChillDateType::class, [
@@ -87,8 +88,6 @@ class SingleTaskType extends AbstractType
     public function configureOptions(OptionsResolver $resolver)
     {
         $resolver
-            ->setRequired('center')
-            ->setAllowedTypes('center', [ Center::class, 'array', 'null' ])
             ->setRequired('role')
             ->setAllowedTypes('role', [ Role::class, 'string' ])
             ;
diff --git a/src/Bundle/ChillTaskBundle/Menu/MenuBuilder.php b/src/Bundle/ChillTaskBundle/Menu/MenuBuilder.php
index 89f511d2a..53751de91 100644
--- a/src/Bundle/ChillTaskBundle/Menu/MenuBuilder.php
+++ b/src/Bundle/ChillTaskBundle/Menu/MenuBuilder.php
@@ -24,7 +24,7 @@ use Chill\TaskBundle\Security\Authorization\TaskVoter;
 use Symfony\Component\Translation\TranslatorInterface;
 
 /**
- * 
+ *
  *
  * @author Julien Fastré <julien.fastre@champs-libres.coop>
  */
@@ -35,13 +35,13 @@ class MenuBuilder implements LocalMenuBuilderInterface
      * @var TranslatorInterface
      */
     protected $translator;
-    
+
     /**
      *
      * @var AuthorizationCheckerInterface
      */
     protected $authorizationChecker;
-    
+
     public function __construct(
         AuthorizationCheckerInterface $authorizationChecker,
         TranslatorInterface $translator)
@@ -50,7 +50,7 @@ class MenuBuilder implements LocalMenuBuilderInterface
         $this->authorizationChecker = $authorizationChecker;
     }
 
-    
+
     public function buildMenu($menuId, MenuItem $menu, array $parameters)
     {
         switch($menuId) {
@@ -69,15 +69,15 @@ class MenuBuilder implements LocalMenuBuilderInterface
     }
 
     public function buildPersonMenu($menu, $parameters){
-        
+
         //var $person \Chill\PersonBundle\Entity\Person */
         $person = $parameters['person'] ?? null;
-        
+
         if ($this->authorizationChecker->isGranted(TaskVoter::SHOW, $person)) {
             $menu->addChild(
                 $this->translator->trans('Tasks'), [
                     'route' => 'chill_task_singletask_list',
-                    'routeParameters' => 
+                    'routeParameters' =>
                         [ 'person_id' => $person->getId() ]
                         ])
                 ->setExtra('order', 400);
@@ -85,18 +85,18 @@ class MenuBuilder implements LocalMenuBuilderInterface
     }
 
     public function buildAccompanyingCourseMenu($menu, $parameters){
-        
+
         $course = $parameters['accompanyingCourse'];
-        
-        // if ($this->authorizationChecker->isGranted(TaskVoter::SHOW, $course)) {
+
+        if ($this->authorizationChecker->isGranted(TaskVoter::SHOW, $course)) {
             $menu->addChild(
                 $this->translator->trans('Tasks'), [
-                    'route' => 'chill_task_singletask_courselist',
-                    'routeParameters' => 
-                        [ 'course_id' => $course->getId() ]
+                    'route' => 'chill_task_singletask_by-course_list',
+                    'routeParameters' =>
+                        [ 'id' => $course->getId() ]
                         ])
                 ->setExtra('order', 400);
-        // }
+        }
     }
 
 
diff --git a/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/AccompanyingCourse/confirm_delete.html.twig b/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/AccompanyingCourse/confirm_delete.html.twig
index 01b7aa499..02a0aa31d 100644
--- a/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/AccompanyingCourse/confirm_delete.html.twig
+++ b/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/AccompanyingCourse/confirm_delete.html.twig
@@ -3,7 +3,7 @@
 {% set activeRouteKey = 'chill_task_task_list' %}
 {% set course = task.course %}
 
-{% block title  'Remove task'|trans %}
+{% block title 'Remove task'|trans %}
 
 {% block content %}
 
@@ -11,8 +11,8 @@
     {
         'title'             : 'Remove task'|trans,
         'confirm_question'  : 'Are you sure you want to remove the task "%title%" ?'|trans({ '%title%' : task.title } ),
-        'cancel_route'      : 'chill_task_singletask_courselist',
-        'cancel_parameters' : app.request.query.get('list_params', { } ),
+        'cancel_route'      : 'chill_task_singletask_by-course_list',
+        'cancel_parameters' : {'id' : task.course.id },
         'form'              : delete_form,
     } ) }}
 
diff --git a/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/List/index.html.twig b/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/List/index.html.twig
index 5b06fabed..c7c622692 100644
--- a/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/List/index.html.twig
+++ b/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/List/index.html.twig
@@ -120,20 +120,20 @@
                                 {% endif %}
 
                                 <li>
-                                    <a href="{{ path('chill_task_single_task_show', { 'id': task.id, 'list_params': app.request.query.all }) }}" class="btn btn-show "></a>
+                                    <a href="{{ chill_path_add_return_path('chill_task_single_task_show', { 'id': task.id }) }}" class="btn btn-show "></a>
                                 </li>
 
-                                {# {% if is_granted('CHILL_TASK_TASK_UPDATE', task) %} #}
+                                {% if is_granted('CHILL_TASK_TASK_UPDATE', task) %}
                                 <li>
-                                    <a href="{{ path('chill_task_single_task_edit', { 'id': task.id, 'list_params': app.request.query.all }) }}" class="btn btn-update "></a>
+                                    <a href="{{ chill_path_add_return_path('chill_task_single_task_edit', { 'id': task.id }) }}" class="btn btn-update "></a>
                                 </li>
-                                {# {% endif %} #}
+                                {% endif %}
 
-                                {# {% if is_granted('CHILL_TASK_TASK_DELETE', task) %} #}
+                                {% if is_granted('CHILL_TASK_TASK_DELETE', task) %}
                                 <li>
-                                    <a href="{{ path('chill_task_single_task_delete', { 'id': task.id, 'list_params': app.request.query.all } ) }}" class="btn btn-delete "></a>
+                                    <a href="{{ chill_path_add_return_path('chill_task_single_task_delete', { 'id': task.id } ) }}" class="btn btn-delete "></a>
                                 </li>
-                                {# {% endif %} #}
+                                {% endif %}
                             </ul>
 
                         </div>
diff --git a/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/_new.html.twig b/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/_new.html.twig
index 37f8b431c..9d324ea85 100644
--- a/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/_new.html.twig
+++ b/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/_new.html.twig
@@ -18,7 +18,7 @@
 
 	<ul class="record_actions sticky-form-buttons">
 		<li class="cancel">
-			<a class="btn btn-cancel" href={% if task.person is not null %} "{{ path('chill_task_singletask_list', { 'person_id': task.person.id, 'list_params': app.request.query.get('list_params', {} )} ) }}" {% else %} "{{ chill_return_path_or('chill_task_singletask_courselist', {'course_id': task.course.id}) }}" {% endif %}>
+			<a class="btn btn-cancel" href={% if task.person is not null %} "{{ path('chill_task_singletask_list', { 'person_id': task.person.id, 'list_params': app.request.query.get('list_params', {} )} ) }}" {% else %} "{{ chill_return_path_or('chill_task_singletask_by-course_list', {'id': task.course.id}) }}" {% endif %}>
 				{{'Cancel'|trans}}
 			</a>
 		</li>
diff --git a/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/_show.html.twig b/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/_show.html.twig
index 1186fb125..26d269191 100644
--- a/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/_show.html.twig
+++ b/src/Bundle/ChillTaskBundle/Resources/views/SingleTask/_show.html.twig
@@ -70,8 +70,8 @@
 
 <ul class="record_actions sticky-form-buttons">
 	<li class="cancel">
-		<a class="btn btn-cancel" href={% if task.person is not null %} "{{ path('chill_task_singletask_list', { 'person_id': task.person.id, 'list_params': app.request.query.get('list_params', {} )} ) }}" {% else %} "{{ chill_return_path_or('chill_task_singletask_courselist', {'course_id': task.course.id}) }}" {% endif %}>
-			{{'Back to the list'|trans}}
+		<a class="btn btn-cancel" href={% if task.person is not null %} "{{ chill_return_path_or('chill_task_singletask_list', { 'person_id': task.person.id } ) }}" {% else %} "{{ chill_return_path_or('chill_task_singletask_by-course_list', {'id': task.course.id}) }}" {% endif %}>
+			{{'Cancel'|trans}}
 		</a>
 	</li>
 
@@ -94,19 +94,20 @@
 		</li>
 	{% endif %}
 
+    {% if is_granted('CHILL_TASK_TASK_DELETE', task) %}
+        <li>
+            <a href="{{ chill_path_forward_return_path('chill_task_single_task_delete', { 'id': task.id } ) }}" class="btn btn-delete">
+                {{ 'Delete'|trans }}
+            </a>
+        </li>
+    {% endif %}
+
 	{% if is_granted('CHILL_TASK_TASK_UPDATE', task) %}
 		<li>
-			<a class="btn btn-update" href="{{ path('chill_task_single_task_edit', { 'id': task.id, 'list_params': app.request.query.all['list_params'] }) }}">
+			<a class="btn btn-update" href="{{ chill_path_forward_return_path('chill_task_single_task_edit', { 'id': task.id }) }}">
 				{{ 'Edit the task'|trans }}
 			</a>
 		</li>
 	{% endif %}
 
-	{% if is_granted('CHILL_TASK_TASK_CREATE', task) %}
-		<li>
-			<a href="{{ path('chill_task_single_task_delete', { 'id': task.id, 'list_params': app.request.query.all['list_params'] } ) }}" class="btn btn-delete">
-				{{ 'Delete'|trans }}
-			</a>
-		</li>
-	{% endif %}
 </ul></div>