Certificate to prove your level of French
For some administrative procedures (for example, an application for a C permit or the naturalisation procedure), the administration will ask to prove your level of French with a certificate.
The Swiss confederation encourages the fide test for one of the official Swiss languages (French, German, Italian). In canton Vaud, these tests can verify a person's level of the French language in terms of written and oral ability. Different organisations offer these language tests. For more information on these tests, go to the fide site. You will also find there a video explaining the fide tests.
Other language proficiency certificates are also recognised in Switzerland, for example, the diploma of French language studies (DELF). For this certificate, you must complete a written and oral French test. For more information on these French tests, visit the website of the Fondation Spirit Francophonie.