"A mexikói zenészek kiállnak a térre és zenélnek."

Translation: The Mexican musicians stand out on the square and play music.

[kebukebu]

Same comment here as my comment about "sit". "Stand" does not like to take prepositions of motion.

Natural sentence ignoring motion: "The Mexican musicians stand out in the square and play music."

Natural sentence including motion: "The Mexicans go stand out in the square and play music."

[Martha94435]

Uh, that's not what "stand out" means. (At least in English, rather than Hunglish.) English really doesn't work like Hungarian in this respect; the only way to really get across the full meaning of "kiállnak" is to use a whole lot more words: The Mexican musicians go outside to stand in the square and then they play music.

[Gertjie-Gaai]

Urgh...not gain: "The Mexican musicians stand out on the square and are playing music" is not accepted

[Andrei551534]

neither is 'are standing out'

[Greybeard.Loon]

The lessons are increasingly pushing us into Hunglish. People will learn Hungarian more easily if they can correlate actual Hungarian with actual English.