Exactly, but not exactly

The basic meanings of ‘exactly’ are:

1 not more and not less – e.g. ‘Is it really important to measure the quantities exactly?’
2 completely / in every way – e.g. ‘You haven’t changed at all – you look exactly the same’.

Apart from these, ‘exactly’ has a number of other common, pragmatic uses, especially in the spoken language.

1 ‘Exactly’ is a common way of expressing complete agreement, sometimes with the suggestion that ‘you’ve expressed what I was thinking, better than I could have done myself’:
‘This sounds as if Beethoven had a hangover when he wrote it.’ ‘Exactly!’
In this use, it typically has falling intonation. When written, it’s often given an exclamation mark, to suggest the energy and enthusiasm it’s often spoken with.

2 ‘Not exactly’ is used as a response to tell someone that they are neither completely right nor completely wrong:
‘So, I hear you’re leaving us.’ ‘Well, not exactly. I’m moving onto a freelance basis, but you’ll still be seeing quite a lot of me here.’
In this use, ‘exactly’ typically has a fall or fall-rise tone. Alternatively, ‘exactly’ can be attached to the end of a negative sentence, in which case it typically has a rising tone:
‘Well, I’m not leaving, exactly.’
‘Well, it wasn’t red exactly – it was a sort of purplish colour.’
(Notice that ‘well’ is often used to introduce statements with ‘not exactly’.)

3 ‘Not exactly’ is used, often with a humorous, exaggerating effect, to say that someone/something falls short of an ideal:
‘I’m not exactly Einstein, but looking at this bill, even I can see that you’ve been overcharged.’
In this use, there is typically stress on ‘not’, and main stress on the ‘ideal’, with a fall-rise or fall:
/ i’m NOT exactly EINstein / (the fall-rise or fall begins on EIN and continues through ‘stein’.)
‘This guidebook was published in 1986.’ ‘Hmm, it isn’t exactly up to date, is it?’
/ it ISn’t exactly up to DATE , IS it? / (fall-rise on ‘date’, fall on ‘is it?’)

4 ‘Not exactly’ is used (also sometimes with a humorous effect) to agree by ‘negating the opposite’:
‘These prices are outrageous.’ ‘(Yes,) they aren’t exactly cheap(, are they?)’
(‘Cheap’ is, in this case’ the opposite of ‘outrageous’.)
‘He wasn’t very helpful, was he?’ ‘(No,) he didn’t exactly bend over backwards(, did he?)
(‘Bending over backwards’ is, in this case, the opposite of ‘not being helpful’.)
‘I wonder when these sandwiches were made.’ ‘(Yes,) they aren’t exactly fresh(, are they?)’
(‘Not fresh’ is, in this case, the opposite of the assumption that sandwiches should be fresh.)

5 ‘Not exactly’ is used for ‘hedging‘ and ‘softening the blow’ – being indirect or diplomatic, and avoiding aggression and confrontation – when disagreeing or criticising:
‘It’s fantastic, isn’t it?’ ‘Well, I wouldn’t go as far as to say that, exactly.’
‘The facilities aren’t exactly what we were led to expect.’
‘That wasn’t exactly what I meant.’

So there’s more to ‘exactly’ than meets the eye, then? Yes, exactly!