This is the 39th most frequent Bulgarian word.
тях
"Them" (third-person plural object pronoun).
"Тях" is used here in a comparative construction, serving as a reference point for comparison to the subject "this house."
Тази къща е по-голяма от тях.
This house is bigger than theirs.
In this sentence, "тях" functions as a prepositional pronoun after the preposition "за" (about), referring to a group of people.
Мисля за тях често.
I think about them often.
The word "тях" here is used as an accusative pronoun meaning "them," serving as the direct object of the verb "виждам" (see).