Subject line in task notifications in other language

Summary

We'd like to change the english prefix in the subject line in task notifications in french

Content

When a task is created, the user receives a mail with either (Action Required: + name of task) or (Completed: + name of task). For our client it is important to have the name of the task in French and the prefix as well.

We can put the name of the task in french, but we'd like to know if we can also influence / change the prefix that is in English in the subject of the mail.

Any tips or pointers are welcome

Thanks