"Is there anybody who wants to learn English? I can help a lot in return for French lessons."
Are you sure of your question form / content ?
You ask about somebody wants to learn English (You are excellent/proficient in English) up till now all is well .Then you offer helping for French lessons in return in return of what ?? You offer helping in both languages ??
Or you wanna say that you can help people with English that you are fluent in in return of helping you with French that you are intermediate in ??
Could please explain more / clarify the question
Thanks in advance