This is the 88th most frequent Serbian word.
тај
"That" (masculine form).
In this usage, 'тај' refers to a particular house, providing identification or emphasis.
Тај дом је изграђен пре сто година.
That house was built one hundred years ago.
In this sentence, 'тај' functions as a demonstrative pronoun, pointing to a specific man who is the speaker's neighbor.
Тај човек је мој комшија.
That man is my neighbor.
Here, 'тај' indicates a specific car, possibly one known to both the speaker and the listener.