This is what we have been accepting on the English side for at least 6 months:
Who wants [the/a] [pink/rose] [t-shirt/tee shirt]?
IMO the definite article is a marginal translation here, but in it went anyway. Of course, neither "a tricko" nor "the tricko" is acceptable on any side of this exercise.
Just saying as a native english speaker, I rarely say and rarely hear t-shirt. (t-shirt is a correct translation. Maybe some regions in the US still call it t-shirt.) I mostly hear/see it when it is in direct contrast to a dress shirt, but even then, I think most will still just say shirt. I do know Czech makes a difference between the two. IMO, Košile is better translated as dress shirt while tričko is just shirt. But, I would just keep košile as shirt and I won't make any comments about it. And sorry about commenting everywhere. Just my last time I didn't, it seemed like you had wanted it. Thanks for your work!
That is very different from my UK experience. And from what American dictionaries like Merriam-Webster say.