It's proper. "Don't" is an abbreviation for "do not" so it's like saying "I do not like", which is correct :]
No, it is not proper grammar. The correct phrasing is "you and I."
I have to HAVE it cleaned.I had to HAVE it cleaned.
No, the correct grammar would be "Look at what you got."
It's not a big deal to say me, Ericka, and Ethan. However, you should probably say: Ericka, Ethan, and I.
Completely my dear sir.
There is nothing wrong with "when will you come?"
It's proper. "Don't" is an abbreviation for "do not" so it's like saying "I do not like", which is correct :]
This is an incomplete sentence,thus being improper grammar.
Because you have improper grammar, (two "you"'s).
The mixed number ab/c is equivalent to the improper fraction (a*c+b)/c
If you are asking if the phrase "Her and her team" is proper grammar, then yes it is. Improper grammar for the same meaning would sound off like, "Her and her's team" or "She and she team." You have it right.
You can, but it is considered improper grammar. Teachers don't like it when you do.
Grammar
The sentence "Lets get into something formal today" is not correct grammar due to improper use of preposition.
No, it is not proper grammar. The correct phrasing is "you and I."
An improper sentence may have incomplete thoughts, lack subject-verb agreement, contain run-on sentences, or have unclear meaning due to poor grammar or punctuation. It fails to convey the intended message effectively and can be confusing for the reader to understand.