Question

We were designing the first macintosh computer (past perfect continuous)

Answer 1

$\huge \mathfrak {Hey \:Mateyy!}$

$\bold {ANSWER :-}$ We had been designing the first macintosh computer.

$\bold {Structure :-}$ Subject + had + been + verb-ing

Answer 2

We had been designing the first Macintosh computer is the past perfect continuous of the sentence: We were designing the first Macintosh computer.

• Past continuous tense makes use of the verb was or were with the "ing" form of the verb. "Ing"
• "Ing" is always added to the first form of the verb.
• In the past perfect continuous tense, we use "had been" with the "ing" form. However, we also use "for or since" as the time is given.
• "For" is used when we are given an indefinite time like four years and "since" is used when definite time is given like 2005.