An year is not correct grammatically. An is only used before a vowel. Year begins with a Y so one would write 'a year'. But an apple; an egg, an institute, an opening, an umbrella. However if a U is pronounced 'yu' as in 'use' or 'Ugandan' then one uses 'a'. A useful thing. A Ugandan man.
No it isn't a grammatically correct word.
no
Grammatically
Yes, "evidenced" is a grammatically correct word. It is the past tense of the verb "evidence," meaning to show or prove something.
The word not is an adverb. It is a word expressing denial, negation or refusal
True
Yes, the sentence is grammatically correct.
a pronoun
The correct spelling of the word "grammatically" is G-R-A-M-M-A-T-I-C-A-L-L-Y.
Yes, it is grammatically correct to end a sentence with the word "so." However, it may be informal or conversational in style.
Neither really. 'In' would be the word to use.
The word "they're is pronounced grammatically correct. It is the shortened version of the words "they are".