A1
も — also, either, even
How も marks “also” and “too” in Japanese, why it displaces other particles, and how it works in negative sentences.
も means also, and it goes after the thing being added.
私も学生です。
Watashi mo gakusei desu.
I’m a student too.
コーヒーも飲みます。
Kōhī mo nomimasu.
I drink coffee as well.
It replaces the particle
も takes the place of は, が and を rather than stacking with them — the same behaviour as は.
私はも学生です。
私も学生です。
も has already taken the topic slot. は and も cannot both mark the same word.
With に and で it does stack: 学校にも行きます, I go to school as well.
In the negative it means either
Same particle, and English switches words.
肉も食べません。
Niku mo tabemasen.
I don’t eat meat either.
Repeated for both
犬も猫も好きです。
Inu mo neko mo suki desu.
I like both dogs and cats.
In a negative sentence the same shape becomes neither: 犬も猫も好きじゃないです. The particle does not change — only the verb at the end does, and once again you do not know which reading was meant until the sentence finishes.
With a question word
何も, 誰も, どこも plus a negative give nothing, nobody, nowhere.
何もありません。
Nani mo arimasen.
There’s nothing.
These only work with a negative verb. 何もあります is not a sentence.