Keeping a conversation going (a propos, wracając do tematu)

Getting in

sorry to bother you, sorry to interrupt

przepraszam, że przeszkadzam — sorry to bother you / to interrupt — the standard opener when you need someone's attention. Przeszkadzać takes the Dative, so with a person it is przepraszam, że panu przeszkadzam.

Changing and holding the subject

by the way, speaking of which (a propos + Genitive)

a propos — by the way, speaking of which — borrowed from French and pronounced a propo. With a noun it takes the Genitive: a propos wakacji.

by the way; while we are at it

przy okazji — by the way; while we are at it — for something you add because the moment suits it.

getting back to the subject

wracając do tematu — getting back to the subject — the phrase that ends a digression. It is the contemporary participle wracając (returning), which you met in the -ąc lesson.

what's the matter? what is it about?

o co chodzi — what is it about? what's the matter? — the question, and also the indirect nie wiem, o co chodzi.

Wrapping up

in short

krótko mówiąc — in short — another participle phrase (mówiąc = speaking).

and so on (itd.)

i tak dalej — and so on — closes a list; in writing it is abbreviated itd.

to get to the point (przejdźmy do rzeczy!)

przejść do rzeczy — to get to the point. Usually as the first-person plural imperative: Przejdźmy do rzeczy!

no problem

nie ma sprawy — no problem — the relaxed answer to a request or an apology.