Are you there? = Dere?/Tere?
Thank you = Thnx/Thnk u/Thnx/ty
What’s up? = Wassup? /Wts up?/ Wtz up?/Sup?
Before = B4
Later = L8r
Night= Ny8
You = u
Are = R
Don’t = Dnt
I don’t know = Idk
As soon as possible = ASAP
Be right back = Brb
What = Wut/Wat
Goodnight = Gn
Take care = Tc