"Traffic lights for cyclists are useful."

Translation: Semafory pro cyklisty jsou užitečné.

[MikhailDidenko]

Semafory jsou užitečné pro cyklisty - is this form really incorrect? Don't you talk this way in your everyday speech?

[VladaFu]

That is something else. Here we have "(Traffic lights for cyclists) are useful.", not "Traffic lights (are useful for cyclists.)."