Learn Finnish: Milloin lapsi syntyi? - When was the child born?

In English, 'to be born' uses the passive voice, but in Finnish, syntyä is an active verb meaning 'to be born' or 'to originate.' The child (lapsi) is the subject doing the action, so the verb is in the standard active past tense: syntyi.

How is the past tense syntyi formed from the infinitive syntyä?

Syntyä is a type 1 verb. To make the third-person singular past tense, you find the stem by dropping the final -ä and then add the past tense marker -i, leaving you with syntyi.

How do I answer this question using a specific date?

Since this question asks 'when' (milloin), you will answer using the rules from this lesson: the ordinal number of the day in the essive case (-na / -nä) plus the month in the partitive case. For example, 'on the third of March' would be kolmantena maaliskuuta.

Can I change the word order to 'Milloin syntyi lapsi?'

Milloin lapsi syntyi? is the standard and most natural word order (Question word + Subject + Verb). While Finnish word order is flexible, putting the verb before the subject here shifts the focus and sounds a bit like 'When was a child born?' rather than asking about this specific child.