Learn Finnish: Odotin sinua, koska autoni oli hajonnut. - I was waiting for you because my car had broken down.

This combination clarifies the exact sequence of events in the past. Odotin (I was waiting) uses the imperfect tense for your main past action. Oli hajonnut (had broken down) uses the pluperfect tense to emphasize that the car breaking down happened even earlier, before the waiting began.

How is the pluperfect tense formed in the phrase oli hajonnut?

The pluperfect is built using the past tense of olla (here, oli for 'it had') followed by the past participle of the main verb. The main verb is hajota (to break down). Because it is a verb type 4 word, you form its past participle by dropping the infinitive ending -ta and adding -nnut, resulting in hajonnut.

Why is the word for 'you' in the partitive case (sinua)?

The verb odottaa (to wait for) is a partitive verb, meaning it always requires its object to take the partitive case. Waiting is considered an ongoing, continuous action with no definite endpoint, which is a classic trigger for the partitive.

Could I say minun autoni instead of just autoni?