Complete the sentence with the correct form of the verb in brackets: "We had already ____ (think) about that risk before the auditor raised it."
Correct answer
thought
Explanation
"Had already" opens a past perfect, which is built with the past participle. This verb collapses both past slots into one -ought spelling, so the participle looks exactly like the past simple, and the regular spelling thinked does not exist in English at all.