French Pronunciation : passé composé / imparfait : Quelle est la différence ?
I have been assuming that verbs have the exact same sound whether they are conjugated in passé composé or imparfait. For example, I thought that chanté and chantais were pronounced the exact same way, and you tell the difference by listening for the preceding words...

J'ai chanté

Question

French Pronunciation : passé composé / imparfait : Quelle est la différence ?
I have been assuming that verbs have the exact same sound whether they are conjugated in passé composé or imparfait. For example, I thought that  chanté  and chantais  were pronounced the exact same way, and you tell the difference by listening for the preceding words...

J'ai chanté  <-- passé composé
Je chantais

Answer

I see you're in Canada. Nowadays, in standard Metropolitan French (i.e. most of France, Belgium, probably Africa), people usually make no distinction between closed E (chanté) and open E (chantais). Thus, the future and the conditional sound the same. However, Quebec accent maintains the distinction, which is as Su.Ki. described. Quebec accent also distinguishes between the open E in mètre and the long open E (realized as a gently gliding diphthong) in maître. Quebec accent also distinguishes “in” and “un”, as well as the open EU in “jeune” and the closed EU in “jeûne”. Also the vowels in “pattes” and “pâtes”. Quebec accent is quite conservative in this regard.

Answer

The 'é' of the passé composé is said with the mouth muscles in quite a tight position, and  the sound is closer to the English 'ay' (think of 'café' and suchlike).

By contrast, the 'ais' or 'ait' of the imperfect is kind of looser and more open, and the sound is closer to English 'e' as in 'egg'.

Those are only very crude approximations, of course.