This is the 175th most frequent Ukrainian word.
там
There.
The word "там" here is used as an adverb indicating a place in the context of the past event.
Вона була там учора.
She was there yesterday.
"Там" functions as a locative adverb specifying a known location revisited by the subject.
Там я вже був раніше.
I have already been there before.
In this sentence, "там" queries about the presence of someone at a specific location.