Idk

Idk means I don't know. If you are clueless then all you have to say is idk. The letters idk can also be useful in texting

Hey friend

Hey

When are you coming to my house

Idk

What does that mean

Seriously...
It means I don't know

Aww thanks I learned something new

Your welcome

Well I will talk to you later

Bye

Bye