Learn Turkish: Yarışmada birinci oldu. - He came first in the competition.

The root is the number bir (one). We add the ordinal suffix -(I)ncI to make it "first". Because bir ends in a consonant and contains the vowel i, 4-way vowel harmony dictates we use the -inci form.

The translation says "came first", but doesn't oldu mean "became"?

Yes! While English speakers say someone "came first" or "took first place" in a competition, Turkish uses the verb olmak (to be / to become). So birinci oldu literally means "he became first".

Why is there a -da attached to yarışmada?

The base word is yarışma (competition). The -da is the locative case suffix, which tells us where something happens (in, on, or at). Together, yarışmada translates to "in the competition".

How do we know it means "he came first" if there is no pronoun like o?

The verb oldu is in the simple past tense for the third-person singular. Because there are no extra personal endings attached (like -m for "I" or -n for "you"), it automatically means "he", "she", or "it". Turkish routinely drops pronouns like o when the verb's ending already gives it away.