Learn Hardcore Turkish: Katı bir plan yapmıştık, ama biraz değiştirdik. - We had made a strict plan, but we changed it a bit.

katı: rigid/inflexible, strict (slightly negative or stern).
kesin: definite/fixed, decided.
sıkı: tight/strict, often efficient/positive (e.g., a tight schedule).
sert: hard/harsh; less natural with “plan.”

yapmıştık is past perfect (pluperfect): it means “we had made.” It backgrounds the plan-making as earlier than the later past action (the changing).

How is yapmıştık built morphologically?

Breakdown: yap- (make) + -mış (resultative past) + idi (past of “be”) + -k (we) → yapmıştık. In speech/spelling, -mış + idi contracts to -mıştı, then you add the person ending: yap-mış-tı-k.

Why is the second clause simple past (değiştirdik) instead of past perfect?

Turkish often uses past perfect to set the background and simple past to narrate the main past event. Here, “we changed it” is the main action that happened after the plan had been made.

Can I say Katı bir plan yaptık instead?

Yes. That puts both actions in simple past (“we made… and then we changed…”). Using yapmıştık adds the nuance “we had already made it (earlier).”

Why is there no object after değiştirdik? Should it be onu or planı?