There was a Postscript section in my English Course-book, which simply teaches the colloquial English phrases as in "Give me a lift", "Let me have a look", "There is no point", etc. But "postscript" won't return any relevant results in Google, so I thought there might be a better expressive/suitable term for this phrases. Is there really?
The phrases are actually titled "social expressions", and that's what I would google for. I might throw in the word "common" for good measure, and search for "common social expressions".
The word postscript has nothing to do with the phrases at hand. It simply means "addendum to the book".