bad english

my english is getting diluted... folks in the office are influencing my linguistic ability on a daily basis.
Yes, is pronounced yest
assuming is pronouced azuming
grammar is worse:
i will does
it does works
i did went
"is it XX?" "yes, this is"
always goes

i'm going mad doing these little corrections in my head everytime i hear something wrong, which is about 20 times per min when they are on the phone, so that i won't get influenced into speaking like that, which i'm starting to.

it's a nightmare