the "Ah"s, somewhat similar to the english "like" and "y'know" are called DISCOURSE MARKERS.
these discourse markers are thought to have a very significant role in facilitating the prediction of the forthcoming words, delineation and such, which are now used by AI researchers to help with speech recognition. initially people thought it would only complicate things, but now some researchers are suggesting these words actually help make things easier. in addition, there is some cognitive work on the importance of taking those mental breaks during the formation of the sentence, although i haven't seen anything yet on cross cultural differences (why do some languages have more of those than others do). although there is this paper about cross cultural issues:
http://www.benjamins.nl/jbp/series/P&C/11-1/art/...

This "eh" thing is really weird to non-Hebrew speakers. When my American copyeditor read quotes by my interviewees, she was very surprised to find lots of "eh"s. She asked me whether this was some word that was endemic to Hebrew. At first I had no clue what she was talking about. For some reason, I had thought that every language had its own conversation-fillers. After giving it some thought, I told her that "eh" was sort of like saying "y'know" or "like". But I'm not sure that's the case.

cette mot c'est ne pas d'accord

*to find the knack of doing sth
*to know a good way of making money
*That's it, i've got it.

*What on earth is that thing?‏¹
*There are loads of things to do in the house.
*It's not bad, that thing of yours.
*Pass me the thingummy/whatsit on the table.

*There's something wrong.
*They told us some dreadful things.
*I've just thought of something.

*Cycling is not my thing.
*What I love are holidays in the country.
*It was a fantastic house, enourmous, by the sea, do you get the idea?

*the trick of the trade
*There's a trick to it.

Qu'est-ce que c'est que ce truc?