"Kik sietnek be az új épületbe?"

Translation: Who is hurrying into the new building?

[MillerDane]

I understand that kik is plural, but I don't think "who are" is possible in English in this context. (Although I am a native speaker, I admit I could be wrong.)

[InkedSkin]

Yes, it is an English irregularity, but in English, we would say 'Who is' in this instance, but not always (eg. Who are they?)