Yes.
You can also say "shows proficiency in"
Yes, "proficient in" is grammatically correct. It is a common phrase used to indicate a high level of skill or expertise in a particular area.
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."
That is the correct spelling of "proficient" (capable, qualified).
"Not like that" can be grammatically correct, depending on the context.
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.
Yes! That is grammatically correct!
Yes, 'for free', is grammatically 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, Almighty God is grammatically correct.
"That was wrong" is a grammatically correct sentence.
Yes, it is grammatically correct.
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.