RULES FOR
QUESTION TAGS:
10) Use correct intonation for speaking: Use falling tone when you're confirming something you expect to be true.
Example: You're John, aren't you? (confirmation)
Use rising tone for genuine questions.
You're John, aren't you? (genuine question)

Let's see usage of question tags in some sentences.

SENTENCE 55:
No one can solve this.
(Add a question tag)

ANSWER IS:
No one can solve this, can they?

RULES:
We use "they (plural)" as the pronoun for "no one" (also "nobody"). The verb is in present tense. Sentence is negative, so question tag is positive.

SENTENCE 56:
I am a good student.
(Add a question tag)

ANSWER IS:
I am a good student, aren't I?

RULES:
We never say: "amn't I?". The correct question tag is 'aren't I?'. This is an exception to the rule.

SENTENCE 57:
We had to work yesterday.
(Add a question tag)

ANSWER IS:
We had to work yesterday, didn't we?

RULES:
The meaning of sentence implies compulsion. "We did have to work yesterday". So, we use "didn't we?" as the question tag.

SENTENCE 58:
Everybody went home.
(Add a question tag)

ANSWER IS:
Everybody went home, didn't they?

SENTENCE 59:
Stop talking.
(Add a question tag)

ANSWER IS:
Stop talking, will you?

RULES:
Question tag "will you?" is used after commands or instructions to sound more polite.

SENTENCE 60:
He would rather eat than study.
(Add a question tag)

ANSWER IS:
He would rather eat than study, wouldn't he?