Update README.md

README.md

@@ -74,20 +74,24 @@ more than one, regardless of the group you are in. This allows for flexible hand
 unforeseen situations.
 
 # Submission of Exercises
-On each exercise sheet some exercises are marked as submissions. You have approximately 
+On each exercise sheet some exercises are marked for submission. You have approximately 
 two weeks for each of these exercises, where the final date is written next to the exercise. 
-In order to get your solutions reviewed, is has to be commited to your GitLab repository 
+In order to get your solutions reviewed, it has to be commited to your GitLab repository 
 following the procedure:
 
 1. For each exercise sheet create a new branch called `sheetX` where `X` is the number of
    the sheet.
 2. Create the new directory following the directory structure as above
-3. Commit your solution to the branch
+3. Commit your solutions to the branch
 4. Create a merge request to your master branch
 
 After final review of your submission (and maybe inclusion of your corrections) 
 you get a :thumbsup: and can merge your branch into your `master` branch.
 
+**Note:** each member of the group should participate in the submission, i.e. 
+commit her/his contributions individually and not just by the creator of the 
+repository.
+
 # Style Guidelines
 All programs you submit should follow basic programming rules like the following: