In normal everyday language we use hundreds, if not thousands of special formulas which are ready-made or fixed expressions and that we use in a very specific situation and that don't fit in any other situation.
The ability of communication is to a high degree bound to the mastery of such formulas. Though this class of formulas is of high importance there is no standard name for it. I have been studying this sector of vocabulary for a considerable time and invented the term Ugf ( umgangssprachliche Formeln) to have a name for this class of formulas.
But I have no English name. My best invention is
"Fixed situational expressions/Fse".
What would you suggest or are there already some terms that are used for this class of formulas?
Another related question. My private collection of what I would call Fse consists of some hundreds of such formulas, I guess. But I would like to know how many Fse we use as an average. I think there must be about two thousand, perhaps even more.
These Fse are different from normal idioms. If you don't know a special idiom you can take a similar one or say it with normal words. But it is very hard to replace an Fse by another expression. Almost impossible. Either you know the Fse or you can't use it.
Best Answer
May then I suggest the term colloquials.
of or relating to conversation : conversational.
used in or characteristic of familiar and informal conversation; also : unacceptably informal.
using conversational style.
Example: the new coworker's rudeness soon began—to use a colloquial expression—to rub me the wrong way.
also: colloquialism, colloquy.