When you summon a Elemental do you need to speak its language to command it?

@JeremyECrawford When you summon a Elemental (Conjure Elemental), do you need to speak its language to command it?

— WahWah Binx (@wahwah_binx) November 23, 2016

Some spells say you summon something and it obeys you. If the spell has no language requirement, there's no language requirement. #DnD https://t.co/j6QBylwsbt

— Jeremy Crawford (@JeremyECrawford) November 23, 2016