It is completely natural to have a little difficulty understanding these tenses, given that they are both the past tense, and when you use them in English, it is almost certainly subconscious; while French will require a little more thought . The simple past (le passé composé) = this tense is used for 'one-off' actions in the past, for example "i ate" (j'ai mangé); actions that started and then finished in the past - i only ate once at that given time. We form this tense by taking the present tense of AVOIR or ÊTRE, and then taking the verb, removing the ending to get the stem, and then adding the following endings; Verbs ending in ER want the ending É to be added - so REGARDER becomes the stem REGARD, and then you add the ending to find the past participle REGARDÉ. So, j'ai regardé means 'i have seen' and vous avez regardé means 'you (plural) have seen' Verbs ending in IR want the ending I to be added - so FINIR becomes the stem FIN, and then you add the ending to find the past participle FINI. So, j'ai fini means 'i have finished' and vous avez fini means 'you (plural) have finished' Verbs ending in RE want the ending U to be added - so VENDRE becomes the stem VEND, and then you add the ending to find the past participle VENDU. So, j'ai vendu means 'i have sold' and vous avez fini means 'you (plural) have sold' Remember, wherever ÊTRE is the auxiliary, the past participle agrees with the subject! The imperfect (l'imparfait) = this tense is used to 'set the scene', or to describe something that went on for an unknown time period [more than just one fixed duration] and could have been regular, for example "i played football when i was young" (quand j'étais jeune, je jouais au foot) or "il pleurait" (it was raining) - the football playing was a habit that happened more than just once, and the weather is a description of the location, which means in both cases the imperfect should be used instead of the simple perfect . We form this by taking the stem of the verb, and then adding the following endings; Je = ais (je pensais - i thought) Tu = ais (tu regardais - you watched) Il / elle / on = ait (il / elle / on dirait - he / she / one said) Nous = ions (nous jouions - we played) Vous = iez (vous nagiez - you [plural] swam) Ils / elles = aient (ils / elles cuisinaient = they cooked) Remember, this tense suggests regularity, while the passé composé suggests a one off action - so j'ai pensé means i thought at that specific time, while je pensais means it was something that i thought for quite a while! And one thing to note is that while verbs ending in -ER, -IR, and -RE are all different in terms of formation in the passé composé, with the imperfect they are all formed the same!These things come with practice, so now try and give me some examples of these tenses in use and try to explain in your own words the difference between them both .