Greetings and politeness (hej, tack, förlåt)

Saying Hello: hej and hej då

Hej is the everyday Swedish greeting and it works at any hour, with anyone — a stranger in a shop, a colleague, a child. Swedish has no formal/informal split here the way German or French does; hej is simply what people say. You will also hear it doubled, hej hej, which is friendly rather than childish.

The farewell is hej då. Two words, and the stress falls on då.

Greetings for the Time of Day

God natt is not a greeting at all — like English good night, it is what you say on the way to bed. Note that both are frozen: god keeps its bare form before the en-word morgon and the en-word natt, and you should learn them as single units rather than assembling them.

Two More Ways to Leave

Vi ses — literally "we see each other" — is the ordinary informal see you. Ha det bra ("have it good") is the warmer take care, and it is what you say when you will not see the person for a while.

Thanking, and the Reply

Tack is thank you. To make it warmer, Swedish lengthens it: tack så mycket. The reply is varsågod — one word in modern Swedish — which does double duty as you're welcome and as here you are when handing something over.

Förlåt is the apology. Okej is the borrowed all-purpose agreement, and it is entirely at home in ordinary Swedish.

Meeting Someone

Trevligt att träffas is what you say when you are introduced — it uses träffas, the reciprocal form of träffa, so it means "pleasant to meet each other". Välkommen welcomes someone who has arrived.