は marks the topic; です is a polite “is/are”. “[Topic] は [what it is] です.”
わたしは マイク・ミラーです。
I am Mike Miller.
ミラーさんは 会社員です。
ミラーさんは かいしゃいんです。
Mr Miller is a company employee.
は (written は but pronounced “wa” when it is the particle) marks the topic — the thing the sentence is about. です comes at the very end and works like “am / is / are”.
Japanese has no articles (a/the) and no separate verb “to be” before the noun — です alone does the job. Word order is fixed: topic first, です last.
です is polite, used in normal, respectful conversation.
The topic は is often dropped when it is obvious from context.
Add か to the end of a statement to turn it into a question. Word order does not change.
ミラーさんは 会社員ですか。
ミラーさんは かいしゃいんですか。
Is Mr Miller a company employee?
ワンさんは 医者ですか。…はい、医者です。
ワンさんは いしゃですか。…はい、いしゃです。
Is Mr Wang a doctor? … Yes, he is.
サントスさんは 学生ですか。…いいえ、学生じゃ ありません。
サントスさんは がくせいですか。…いいえ、がくせいじゃ ありません。
Is Mr Santos a student? … No, he isn't.
あの方は どなたですか。
あのかたは どなたですか。
Who is that person? (polite)
Japanese forms questions simply by adding the particle か at the end — there is no need to invert the word order as in English.
The answer starts with はい (yes) or いいえ (no) and then repeats the predicate: はい、医者です / いいえ、医者じゃ ありません. There is no short “yes, he is” — the noun comes back, in the affirmative or the negative form.
どなた is a polite word for “who”; the plainer word is だれ.
In everyday speech the repeated noun is usually dropped in favour of はい、そうです / いいえ、ちがいます — lesson 2 covers そうです.
の joins two nouns: N2 is the main word, N1 is extra information about it (belonging, group, type). “N1's N2 / N2 of N1”.
ミラーさんは IMCの 社員です。
ミラーさんは IMCの しゃいんです。
Mr Miller is an employee of IMC.
わたしは 日本語の 先生です。
わたしは にほんごの せんせいです。
I am a teacher of Japanese.
N2 is the main noun — the thing the phrase actually refers to. N1 is extra information that narrows it down: whose it is, which company or group it belongs to, what kind it is. IMCの 社員 is a 社員 (an employee); IMC only says which employee.
The order is fixed, and it is the reverse of English “of”: extra information + の + main noun. Whatever stands last is what the phrase is about.