Learn Turkish: Fıstık yemiş olabilir, bu yüzden dudağı şişmiş olabilir. - He might have eaten peanuts, so his lip might have swollen.

This structure combines a verb with the indirect past suffix -miş (used for things you deduce or didn't directly witness) and the auxiliary olabilir (it is possible / it can be). Together, a phrase like yemiş olabilir literally implies "It is possible that he ate [it] (and I didn't see it)." It is the standard way to express "might have [done something]" in Turkish.

Could we use the direct past tense and say "yedi olabilir" instead of yemiş olabilir?

No. When you are expressing a possibility about a past event, you are making a guess or a deduction rather than stating a known fact. Therefore, you must use the deductive past suffix (-miş) on the main verb before the auxiliary olabilir.

Since there is no O (He) at the beginning of the sentence, how do we know it's about "him"?

The auxiliary verb olabilir has no personal ending, which by default indicates the third-person singular ("he," "she," or "it"). Additionally, dudağı (his/her lip) uses the third-person possessive suffix -ı, confirming we are talking about a specific third party.

Why is it written as dudağı instead of "dudakı"?