Once you have been living in France for a while, your language skills improve, beyond being able to order your morning pain in the boulangerie. We have been here for almost 8 years now and now that I am more confident in speaking French (I label myself competent rather than fluent) I want to use more subtlety in my speaking, and to be as correct as I can be...no French person is ever going to mistake my strong English accent for a native one, but I hope at least they realise that I can speak the language.
So I am keen to use the right term when there are (seemingly) several you can use in any given situation.
My favourite example is bonjour and bonsoir and at what moment of the day you should switch from one to the other. Mark was taught at school that it is 6.00pm and so he sticks to this rule (and why not?) Claudine, wife of our local mayor and also a friend, knows this, and so when we meet in the late afternoon/early evening she makes a great show of looking at her watch before greeting Mark 'appropriately'! My own experience of when to use which word has lead me to the conclusion that the rule is...whatever word I choose the person I am greeting ALWAYS uses the other!! So at 'that' time of day, I wait for my friends to say hello first and just copy whatever they say!
Another interesting phrase (or phrases) is the translation of 'see you soon'. Easy, right...it's à bientôt? Well, sometimes but not usually. Again, it all depends. My unscientific study of this phrase has led me to the following rules of thumb:
If you are going to see someone very soon (for example, I phone a neighbour to ask if I can pop round now to visit) you use à toute suite - see you straight away.
If I phoned this friend though and arranged to call round an hour later, I would say à tout à l'heure - see you later.
If I phoned in the morning to arrange an afternoon visit - à cet après-midi - see you this afternoon -would be used.
When chatting with someone and on leaving, you want to say 'see you soon', what you say still depends...if its someone you see regularly (a mum outside the school gates) then à demain - see you tomorrow - will be good. A friend you see from time to time with no regularity - à plus - see you again - and a friend who you see fairly often would (at last) get the phrase à bientôt.
Even though I know the theory of all the above, I still regularly use the 'wrong' phrase, but as we say here in France c'est pas grave!