Conjugations for nouns and な-adjectives

Question 1

です

Answer 1

Positive-non past, for nouns and な-adjectives
Formal and informal(Drop です, to be even less formal)
です can be added to any informal noun/

Question 2

ではありません

Answer 2

Negative non-past for nouns and な-adjectives

Formal

Question 3

でした

Answer 3

Positive past, use with nouns and な-adjectives

Formal

Question 4

ではありませんでした

Answer 4

Negative past, for nouns and な-adjectives

Formal

Question 5

だ

Answer 5

Positive-non past, for nouns and な-adjectives
Informal
だ can be used in formal speech when an emotion or an extreme reaction calls for it, and it’s a declarative, so you sound like you are in charge and the boss. Most of the time in speech(formal and informal) です is used instead

Question 6

だった

Answer 6

Positive past, use with nouns and な-adjectives

Informal

Question 7

ではない/じゃない

Answer 7

Negative non-past for nouns and な-adjectives
Informal
The は in “ではない” is pronounced as the kana わ

Question 8

ではかった/じゃなかった

Answer 8

Negative past, for nouns and な-adjectives
Informal
The は in “ではかった” is pronounced as the kana わ

Question 9

What happens is you add です to the end of informal noun and な-adjective conjugations?

Answer 9

It makes them more polite