I have a feeling that "quite pretty" doesn't have exactly the same meaning in British English and American English. For instance, in American English, "She's quite pretty" is considered as a compliment, and is close in meaning with "She's very pretty", whereas in British English, "She's quite pretty" has more or less the meaning of "She's rather pretty", "She's okay", but not "very pretty", which means that "quite pretty" is not "quite a compliment" in British English. What do British and American native speakers think? What would an Austalian or a Canadian think?
EL&U member Farid points the way in his comment earlier. The Longman Online Dictionary (http://www.ldoceonline.com/dictionary/quite) differentiates between American and British English usages. Starting with American English usage:
1 (Especially American English) Very, but not extremely:
'The food in the cafeteria is usually quite good'; 'His hair is quite thin on top now'; 'Amy's at college, and she's doing quite well'; 'He's quite a good soccer player.'
Longman also lists some usages without attributing them to either side of the Atlantic:
3 Quite a lot/bit/few - a fairly large number or amount:
'He's got quite a lot of friends; 'Quite a few towns are now banning cars from their shopping centres.'
5 Not quite - not completely:
'They weren't quite ready so we waited in the car; 'I'm not quite sure where she lives.; Dinner's almost ready, but not quite.'
6 Not quite why/what/where etc - not exactly why, what, where etc:
'The play wasn't quite what we expected.'
Longman suggests that the following are more representative of British usage:
2 (Especially British English) Fairly, or to a small extent, but not very:
'The film was quite good, but the book was much better'; 'I got a letter from Sylvia quite recently'; 'I quite like Chinese food.'
4 (British English) Completely:
'I'm sorry. That's quite impossible'; 'What she's suggesting is quite ridiculous!'; 'I think you've had quite enough to drink already!'; 'That's quite a different matter.'
7 (British English) Quite a something/quite some something. - Used before a noun to emphasize that something is very good, large, interesting etc:
'That was quite a party you had.'; 'The engines make quite a noise.'; 'It's quite some distance away.'
8 (Especially British English) Quite a/some time. - A fairly long time:
'We've been waiting for quite some time now.'
9 (British English) Quite right. - Used to show that you agree strongly with someone:
'I refuse to do any more work.' 'Quite right. They can't expect you to work for nothing.'
10 (British English) That's quite all right. - Used to reply to someone that you are not angry about something they have done:
'I'm sorry we're so late.' 'That's quite all right.'
11 (British English formal) Quite/quite so. - Used to show that you agree with what someone is saying [= exactly]:
'They really should have thought of this before.' 'Yes, quite.'
12 (especially British English) Quite something - Used to say that someone or something is very impressive:
'It's quite something to walk out on stage in front of 20,000 people.'
Longman's Dictionary goes on to observe in relation to American and British English usages:
In British English,using quite suggests you are not very enthusiastic about something. In American English, quite is a stronger way of qualifying an adjective. In both British and American English, the way you say the word is important. In British English, if you say It was quite good and you put the emphasis on the quite, you mean it was good, but not very good. If you put the emphasis on good, you mean it was very good. In British English, when it is used with adjectives like impossible or unacceptable, it means completely, and you put the emphasis on it. In American English, the emphasis is always on the adjective that goes with quite.
Please note that I have made some formatting changes to the Longman text in order to address the question here more clearly. The text in the original format can be accessed at the link above.
It is interesting to consider how 'quite' came to take up this role in signalling emphasis, affirmation, calculation and approximation in language. My understanding is that 'quite' is related to 'quit', but not 'quit' in the commonly understood sense of 'resign', but in it's original (and now obscure) sense of 'calculate, balance, or close an account'.
The OED clearly attributes 'quite' to 'quit' but has nothing to say about the development of the word.
quite ▪ I.quite, adv.
(kwaɪt) Forms: 4–6 quit, quyte, 5 Sc. quhyt, 5–6 quyt, 6 quyght, 6–7 quight, 4– quite.
[f. quite quit a.]
▪ III.quite obs. form of quit a. and v.; white.
When we get to 'quit' in the OED we have to wade through the alternate sense of 'leaving' or 'resigning'. I suggest in my response to EL&U question, How did 'to quit' evolve to mean 'to behave or conduct in a specified way'? that this is essentially the secondary sense, and that the primary sense relates to balancing and closing accounts. Again the OED, in respect of 'quit':
II. 10. To repay, reward, requite (a person with some return for something done). Obs. exc. north. dial. (in phr. God etc. quite, white, twite).
13.. E.E. Allit. P. A. 595 Þou quyteȝ vchon as hys desserte. c 1384 Chaucer H. Fame iii. 524 We han well deserued hyt, Therfore is ryght that we ben quyt. c 1440 Generydes 6975 Thus quyte he them that were to hym so kynd. c 1530 Ld. Berners Arth. Lyt. Bryt. (1814) 178 Syth he had done me one displeasure, I shall quite him agayne with two. 1576 J. Woolton Chr. Manual C i, Let vs not with like thanks quite almightye God for his greate benefyts bestowed vppon vs. 1599 Massinger, etc. Old Law ii. ii, When I visit, I come comfortably, And look to be so quited. 1664 Butler Hud. ii. i. 448, I understand..how to quit you your own way.
So, whenever we say 'quite' we are essentially saying something like: 'by accounts', or 'by my calculation', or 'as the accounts say', or 'considering the balance', or 'as the sums tell us'. Essentially the speaker is referencing an unsubstantiated external authority or body of knowledge or process of developing knowledge to give weight or qualification to an opinion or view that they hold personally.
It is no surprise that it is such a commonly (and carelessly) used word, given that as humans we are very fond of putting our opinions forward, and in the absence of certain knowledge, suggesting with the word 'quite' that the opinion (for better or worse) is not ours alone but references some 'higher' or 'wider' source. One might imagine in future centuries the word 'quite' might have been replaced in this usage by 'wiki'.
If I met a woman for the first time, who clearly wasn't attractive, and someone asked for my opinion I might say:
Well..., she's not bad-looking. (= she's quite unattractive)
If the woman was on the plain side...
Not bad, I suppose (= could be worse). Her legs are quite nice (= nothing to write home about).
If the woman is just out of her teens, but you could tell she's destined to be beautiful
She's quite beautiful, isn't she?
A young fresh-faced teenager
She looks quite pretty
Would the comments in brackets be the same for an American English speaker? I'm not sure, maybe or maybe not. According to Wikipedia and Macmillan, it appears that my She's quite beautiful is equivalent to their She's quite pretty, whereas Her legs are quite nice to an American speaker would mean they are indeed very nice-looking. I think the clue to understanding the speaker's meaning lies in their body language, facial expressions, and of course, intonation. All things quite difficult to render on the page.
Wikipedia says this on the BrEng and AmEng divide
Macmillan Dictionary has this succinct note
Differences between British and American English: quite
In British English quite usually means ‘fairly’: The film was quite enjoyable, although some of the acting was weak. When American speakers say ‘quite’, they usually mean ‘very’: ♦ We’ve examined the figures quite thoroughly. Speakers of British English sometimes use ‘quite’ to mean ‘very’, but only before words with an extreme meaning: ♦ The whole experience was quite amazing.
The Macmillan blog also provides this example, and I find myself agreeing with them on this point.
If your American boss says your work is quite good, should you be pleased or a little concerned? In British English quite good only means pretty good or fairly good, but in American English it’s much more positive. Quite good means very good, so you can give yourself a pat on the back.
I guess it depends on the subjective value of the adjective, for something can be more or less true, or quite true, or something can be more or less pretty, or quite pretty.
However, an adjective such as "true" is less subjective than "pretty", for something is often considered as either true or not true, with no in-between gradient in the value of the adjective. In this case, "quite true", with the meaning of "completly true", seems to be mainly a British use. In the US, it would be more common to say "Absolutely!", "Definitely" or "For sure!', instead of "Quite true!" or "Quite so!".
For an adjective such as "pretty", it is easier to ascribe a continuous gradient or scale between what is not pretty (at all) and what is very pretty, with a lower norm (a little less than pretty) and an upper norm (a little more than pretty).
In this case "quite" upgrades moderatly the norm of "pretty" in British English, whereas it upgrades it to a value nearby "very pretty" in American English.
Nevertheless, the Longman Dictionary points out that in British English, if you say It was quite good, and you put the emphasis on the quite, you mean it was good, but not very good, but if you put the emphasis on good , you mean it was very good.
The Longman Dictionary also points out that in Americant English, the emphasis is always on the adjective that goes with quite, which is different in British English since you can put the emphasis either on quite or the adjective (with diffence in meaning : good, but not very good / very good).
Therefore, if you follow the indications of the Longman Dictionary, "quite good" can also mean something close to "very good" in British English, but only if the emphasis is on "good", whereas in American English the emphasis is always on "good" and it always means something close to "very good".
As far as the etymology, "quite" is cognate with the French verb "quitter", which means "leave" or "cease". It also gave "quiet" and "quit", when for instance you order to stop chatting, and that somehow you leave noise for silence as you ask to quit / stop the activity of chatting (Be quiet! Stop chatting!).
In "quite pretty", you bluntly leave the norm of what is pretty in American English, to reach a value close to "very pretty", whereas you barely leave the norm in British English (just a little better than average): in this case "she's quite pretty" is not such a compliment for a lady in Britain (pretty, but not very pretty), and the emphasis should be on the adverb quite, but it might as well mean "very pretty" if the emphasis was on pretty (to be verified).
In "quite true", you leave the field of what is not true, what could be true but to a lesser extent, or what could be not so true, to mean completly true or thoroughly true.