Intonation

English tags can have a rising or a falling intonation pattern. We may contrast this with French or German, for example, where all tags rise. As a rule, the English rising pattern is used when soliciting information or motivating an action, that is, when some sort of response is required. Since normal English yes/no questions have rising patterns (e.g. Are you coming?), these tags make a grammatical statement into a real question:

• You're coming, aren't you?
• Do listen, will you?
• Let's have a beer, shall we?

The falling pattern is used to underline a statement. The statement itself ends with a falling pattern, and the tag sounds like an echo, strengthening the pattern. Most English tag questions have this falling pattern.

• He doesn't know what he's doing, does he?
• This is really boring, isn't it?

Sometimes the rising tag goes with the positive to positive pattern to create a confrontational effect:

• He was the best in the class, was he? (rising: the speaker is challenging this thesis, or perhaps expressing surprised interest)
• He was the best in the class, wasn't he? (falling: the speaker holds this opinion)
• Be careful, will you? (rising: expresses irritation)
• Take care, won't you? (falling: expresses concern)

Sometimes the same words may have different patterns depending on the situation or implication.

• You don't remember my name, do you? (rising: expresses surprise)
• You don't remember my name, do you? (falling: expresses amusement or resignation)
• Your name's Mary, isn't it? (rising: expresses uncertainty)
• Your name's Mary, isn't it? (falling: expresses confidence)

It is interesting that as an all-purpose tag the London set-phrase innit (for "isn't it") is only used with falling patterns:

• He doesn't know what he's doing, innit?
• He was the best in the class, innit?

On the other hand, the adverbial tag questions (alright? OK? etc.) are always found with rising patterns.

[edit] Emphasis

English tag questions are normally stressed on the verb, but the stress is on the pronoun if there is a change of person.

• I don't like peas, do you?
• I like peas, don't you?

This is often a rising tag (especially when the tag contains no negation), or the intonation pattern may be the typically English fall-rise. In French, this would be expressed with et toi?, which is also a kind of tag question.