noun
T-shirt, tee (shirt)
A2
T-Shirt: neuter noun meaning 'T-shirt' or 'tee'. Plural T-Shirts (regular, written with hyphen or capital). Declension: das T-Shirt (Nom sg), die T-Shirts (Pl). Borrowed from English; behaves like a regular noun in German with standard plural formation and typical declension endings.
Examples
Ich trage ein T-Shirt.
I'm wearing a T-shirt.
Er trägt heute ein weißes T-Shirt.
He's wearing a white tee today.
Der Freund zog seinem Bruder ein neues T-Shirt an, weil dieser sich vor dem Treffen frisch machen wollte.
The friend put a new T-shirt on his brother because he wanted to freshen up before the meeting.
Details
Mnemonics
Visualize a plain T-shirt with a big 'T' on the chest
Like English 'T-shirt' (same word)
das — think 'das T-Shirt' like a neutral object (das Kleid vs die Hose)
Notes
Loanword from English; plural commonly written T‑Shirts. Often treated as neuter in German.