There are a large number of French loanwords in English, and an additional large number of Latin-derived words which have cognates. French is also adopting many English loanwords, much to the chagrin of the Académie française. There are however a large number of false friends between English and French.
Contrastive analysis also highlights differences in tense use.
French L1 speakers often have difficulties with the consonant sounds /θ/ /ð/ and h, which do not exist in French, and are typically substituted with /s/ /z/ and h-dropping. French vowel sounds are also somewhat different, and lacking diphthongs, students often have problems with these.