"Jsou to města."

[ibelcic]

Why do you use "to" and not "ta"?

[tragram]

TO means THOSE here. In TA MĚSTA, TA means THE. I hope it's clearer now. :)

[Somi401851]

why can not use Ta instead of to?
and does it look like to a question? does not?

[ElenaNnn1]

towns - it is not cities

[VladaFu]

both are correct