"That was wrong" is a grammatically correct sentence.
the n needs to be "and"
Yes. There's nothing wrong with it grammatically.
no it is not grammatically wrong but it is better to ask where are you if you want to use it in question...
Only #1 is grammatically incorrect, although the question itself is grammatically wrong. It should read "Which of the following sentences is grammatically right." There is more than one sentence so it needs to be "sentences", not "sentence". Number 1 is wrong: it should be "This will remain between you and me" The object of the preposition "between" needs an accusitive form. Number 3 is also wrong, but it is not grammatically wrong. "Lays" is a transitive verb; you need the intransitive "lies" so the sentence should say "He lies on the couch" That is an error in vocabulary, not grammar. As well, the "i" in number 2 and the "he" in number 3 should be capitalized. Capitalization is not grammar.
Grammatically correct, maybe, but idiomatically wrong. We normally say "buy it for me."
yes
No, the sentence should be "he went into the sea alone" to be grammatically correct.
the n needs to be "and"
That sentence is grammatically sound. If you are writing formally, don't use conjunctions.
Personally, I don't think there is anything wrong with it. Personally, I believe I am correct.
No.
Yes. There's nothing wrong with it grammatically.
no it is not grammatically wrong but it is better to ask where are you if you want to use it in question...
Only #1 is grammatically incorrect, although the question itself is grammatically wrong. It should read "Which of the following sentences is grammatically right." There is more than one sentence so it needs to be "sentences", not "sentence". Number 1 is wrong: it should be "This will remain between you and me" The object of the preposition "between" needs an accusitive form. Number 3 is also wrong, but it is not grammatically wrong. "Lays" is a transitive verb; you need the intransitive "lies" so the sentence should say "He lies on the couch" That is an error in vocabulary, not grammar. As well, the "i" in number 2 and the "he" in number 3 should be capitalized. Capitalization is not grammar.
Could you please provide the sentence in question so that I can help you determine if it is correct?
No, it is grammatically wrong and contains a spelling error.
The sentence is grammatically incorrect. It should be structured as "Taking a psychology test," with the subject preceding the action.