This is the 13th most frequent Greek word.
τις
"Τις" means "someone," "anyone," or "some" depending on context.
In this sentence, 'τις' is used as the definite article for a feminine plural noun, meaning 'the'.
Μου δίνει τις μπανάνες.
She gives me the bananas.
Here, 'τις' is used as an article for the accusative case in feminine plural form to specify 'these days'.
Ποιες είναι αυτές τις μέρες;
What are these days?
In this sentence, 'τις' is a personal pronoun in the accusative case, meaning 'them', referring to a group of feminine plural objects or individuals.