The French Imperfect Tense

Uses
This tense is used to represent an incomplete event in the past, a habit in the past or when the word was is used in English.

Formation

First the we form of the present tense of the verb must be found and the -ons removed.  For example, with avoir the imperfect stem is av.  Then the imperfect endings must be applied.  These are:

-ais          -aions

-ais          -aiez

-ait           -aient

So for i was having you would say in French, j'avais.

Irregulars

There is only one irregular in the imperfect tense and that is être.  This is because the we form of être

 in the present tense doesn't end in -ons.  The imperfect stem for être in French is therefor ét.