"They want shirts."
Translation:Tá léinte uathu.
what did I miss? I have a slew of "teastaionn ... uathu" for "they want" or "they need" in this lesson, then I am marked off for it here and it's "ta leinte uathu" for "they want shirts." I am doing this lesson the first time at the moment so I'm sure I am just missing something basic, but ... help? Why "ta" instead of "Teastaionn" here?
In some dialects, bí ó and teastaigh ó are interchangeable for the meaning 'want'. If teastaigh wasn't accepted, please report.
In Connacht, though, it can only mean 'need'
Are they interchangeable in Ulster's Irish because that is the dialect I eventually want to look further into after finishing the Duo course.
Unfortunately, I don't know know enough about Ulster Irish to answer. Your best bet would be to ask on AnLonDubhBeag's stream.