As in someone trying to remember where they left off, "Where was I?" is correct, yes.
No, the correct phrasing would be "Where was I?" to form a complete and grammatically correct question.
The phrase "You are not knowing" is not grammatically correct. Instead, you can use "You do not know" or "You are not aware."
Yes, "He sailed his boat on the river" is grammatically correct.
The phrase "Is you don't miss me do you" is not grammatically correct. It should be rephrased to something like "Don't you miss me?" to be correct.
No, it is not grammatically correct. The correct way to say it is "your older sister."
No, the grammatically correct sentence would be: "I am annoyed by the way you behave."
"Not like that" can be grammatically correct, depending on the context.
Yes, 'for free', is grammatically correct.
Yes! That is grammatically correct!
The phrase "Is you don't miss me do you" is not grammatically correct. It should be rephrased to something like "Don't you miss me?" to be correct.
The phrase "You are not knowing" is not grammatically correct. Instead, you can use "You do not know" or "You are not aware."
Yes, it is grammatically correct.
Yes, Almighty God is grammatically correct.
"That was wrong" is a grammatically correct sentence.
The sentence "Rhoda's Crazy" is not grammatically correct. It is missing a verb to make a complete sentence.
'What a drunkard you are' is a grammatically correct English sentence.
"For free' is grammatically correct. It is an idiom of the English language.
The sentence is grammatically correct.