There are no formal english lessons during the fifth year. You should now be perfectly autonomous. However, please keep in touch via e-mails or via discussions as your work develops. English is obviously a bonus to your work. Exploit websites, texts and books for background research and generally broaden your knowledge by finding out what other designers are doing outside France. I also encourage you to contact designers you admire. Ask them if they will accept you in their studio or agency either as part of your work experience, an internship agreement, placement study or even as a paid job (e.g. assistant, tea-lady, general dogsbody...).
Now is the ideal time to think about your portfolio. I recommend you make at least an engish version of your C.V. but a complete portfolio either on paper or in the form of a website is much better and you will not regret the effort. Feel free to get in touch for help and advice.
Also ask if you need help writing letters to obtain grants, enter competitions or make applications for other university courses. Models and guidance are on-line and available for download. Just ask.
The only real obligation this year is to produce an english language abstract that will be printed with your fifth year dissertation...
Clarifying ideas about work for your final year projects is vital in the run-up to your diploma. Doing it in english may help organize and prioritize some of the issues and methods you have been using.