imperfect tense
Definition - Any tense that denotes a past action that is still in progress.

Example -

(1) When I walked to the store, I was thinking of you.
(2) Every Tuesday I used to eat hot dogs.

Oxford English Dictionary -
Its first citation is from 1530:
"The preter imperfit tens, as je parloye."
(Jehan Palsgrave, Lesclarcissement de la langue françoyse, 84)

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