Question

Using simple past or past continuous
They _______(paint) the house all day yesterday.​

Answer 1

Answer:

They were painting the house...................

Answer 2

Answer:

They were painting (paint) the house all day yesterday.

here we can use past continuous tense because this was the action that was happening in the past.

we used were as the subject is plural (they)

we used were+painting for past continuous tense

hope this helps