Kan du säga den exakta tiden, eller vet du bara ungefär?

Because this is a yes/no question in Swedish.

• Du kan säga den exakta tiden. = You can say the exact time.
• Kan du säga den exakta tiden? = Can you say the exact time?

In Swedish, direct yes/no questions normally put the finite verb first and the subject after it.

Literally, it means can you say.

• kan = can / are able to
• du = you
• säga = say / tell

In this sentence, säga is being used in the sense of state or tell the time.

Because the sentence means the exact time, not just exact time in a general sense.

Swedish often uses double definiteness with adjectives:

• den = the
• exakta = exact
• tiden = the time

So den exakta tiden literally looks like the exact the-time, but that is normal Swedish grammar.

Compare:

• en exakt tid = an exact time
• den exakta tiden = the exact time

Because adjectives change form in Swedish.

Here, tid is a common gender noun, and the noun phrase is definite: den exakta tiden.

In definite forms with adjectives, Swedish normally uses the -a form of the adjective:

• en exakt tid = an exact time
• den exakta tiden = the exact time

So exakta is the expected form here.

This is the same double definiteness pattern.

When a definite noun has an adjective before it, Swedish usually marks definiteness twice:

1. with a separate word like den
2. with the definite ending on the noun, here tiden

So:

• tiden = the time
• den exakta tiden = the exact time

You cannot normally drop either one in standard Swedish in this kind of phrase.

Because the second part is also a direct question.

After eller (or), Swedish starts a new clause, and that clause keeps normal question word order:

• vet du = do you know
• not du vet in a direct question

So the structure is:

• Kan du säga ...
• eller vet du ...

Both parts are question clauses.

It means only roughly, just approximately, or only more or less.

• bara = only / just
• ungefär = approximately / roughly

So vet du bara ungefär? means something like:

• do you only know approximately?
• do you only know roughly what time it is?

The second part leaves some words understood from context.

Because Swedish, like English, often leaves out words that are obvious from context.

The full idea could be something like:

• ... eller vet du bara ungefär vad klockan är?

But that extra part is omitted because the listener already knows the topic is the time.

So vet du bara ungefär? is a natural shortened version.

They are doing two different jobs:

• säga = say / tell / state
• veta = know

So the sentence contrasts two ideas:

1. Can you state the exact time?
2. Or do you only know it approximately?

In other words, it asks whether the person can give a precise answer or only a rough one.

It is understandable and perfectly possible Swedish. It sounds a bit careful and explicit.

A Swede might also say:

• Kan du säga exakt vad klockan är, eller vet du bara ungefär?
• Vet du exakt vad klockan är, eller bara ungefär?

Your sentence is still fine; it just uses den exakta tiden as a very clear noun phrase.

Yes. In modern Swedish, du is the normal way to address almost everyone.

Unlike some languages, Swedish usually does not need a special formal you in everyday situations. So:

• Kan du ...? is normal and not rude.

Not necessarily.

Many Swedish writers would simply write:

• Kan du säga den exakta tiden eller vet du bara ungefär?

The comma can be used to mark a pause or make the two alternatives a little clearer, but it is often omitted in modern Swedish before coordinating words like eller. Both versions are acceptable.