Geturðu sagt það einu sinni enn?

Geturðu means can you here.

It is a contraction of getur þú:

• getur = can / is able to
• þú = you (singular, informal)

In questions, Icelandic often attaches þú to the verb, so getur þú becomes geturðu. Both are understandable, but geturðu is the very common natural form in speech and writing.

Because this is a yes/no question.

In Icelandic, yes/no questions usually begin with the finite verb:

• Geturðu sagt það...? = Can you say that...?

This is similar to English, where we also move the verb forward:

• You can say it.
• Can you say it?

So the verb-first order is completely normal here.

After geta in this meaning, Icelandic normally uses the verb in the form sagt with segja.

So you learn this as a pattern:

• geta sagt = be able to say / can say

That means:

• Geturðu sagt... = Can you say...

For learners, it is often easiest just to memorize:

• segja = to say
• sagt = the form used in expressions like geta sagt

So Geturðu segja það... would not be the normal form here.

Það means it / that and is the object of sagt.

It refers to whatever the other person just said:

• Geturðu sagt það... = Can you say that / it...

English can also do this:

• Can you say that again?
• Can you say it again?

Icelandic uses það very naturally in this sentence.

Literally, it is something like one time again/still more, but the natural meaning is:

• once again
• one more time

As a learner, the easiest approach is to treat einu sinni as a common chunk meaning once / one time, and then enn adds the sense of again / one more here.

So:

• einu sinni enn = one more time

Yes. Geturðu sagt það aftur? is also very natural and common.

The difference is small:

• aftur = again
• einu sinni enn = once again / one more time

So:

• Geturðu sagt það aftur? = a very normal everyday way to say it
• Geturðu sagt það einu sinni enn? = slightly more explicit about repeating it one more time

Both are good Icelandic.

Yes. It is a normal, polite everyday request.

Geturðu... ? literally looks like Can you... ?, but in Icelandic it is commonly used to make requests, just as in English.

If you want to sound even softer, you could say:

• Gætirðu sagt það einu sinni enn? = Could you say that one more time?

But the original sentence is already perfectly natural and polite in ordinary conversation.

A useful approximation is:

• þ sounds like th in thing
• ð sounds roughly like th in this

So in this sentence:

• það starts with the thing sound
• the ð in geturðu is the softer this-type sound

A rough English-friendly pronunciation of the whole sentence could be written as:

GEH-tur-thu sakht tha EY-nu SIN-ni ent

That is only an approximation, but it can help you get started.

Yes, segja can cover both say and tell in different contexts, but in this sentence the most natural English translation is say or repeat.

So here the idea is:

• Can you say that again?
• Can you repeat that?

It is not really about tell a story again or tell someone something in the broader sense. In this context, it is simply asking for repetition.

You change you from singular þú to plural þið:

• Getið þið sagt það einu sinni enn?

That means:

• Can you all say that one more time?

So the pattern is:

• singular: Geturðu sagt það einu sinni enn?
• plural: Getið þið sagt það einu sinni enn?