Þetta dugir í dag.

A word-by-word breakdown is:

• Þetta = this
• dugir = is enough / suffices / will do
• í dag = today

So the whole sentence means something like:

• This is enough today
• This will do for today
• This suffices for today

The most natural English version often depends on context.

Þetta is the neuter singular form of the demonstrative pronoun meaning this.

It can refer to:

• a thing: this thing
• a situation: this
• an amount or result: this is enough

In this sentence, þetta is the subject of the sentence: the thing that is enough.

The dictionary form is duga, which means to suffice, to be enough, or to do in the sense of be adequate.

In the sentence, the verb is conjugated for third person singular present, because the subject is þetta = this.

So:

• að duga = to suffice / to be enough
• þetta dugir = this is enough / this will do

A few present-tense forms are:

• ég duga = I suffice / I am enough
• þú dugir = you suffice
• þetta dugir = this suffices

Not always exactly, but it is very close.

Að duga is often used where English would say:

• be enough
• do
• be sufficient
• serve for now

So Þetta dugir í dag can sound more natural in English as:

• This will do for today
• This is enough for today

Even if suffice is accurate, it is often more formal than the natural English translation.

Because í dag is a fixed, very common expression meaning today.

The noun dagur means day, and in this phrase the form is dag. You should learn í dag as a whole expression.

Even though í can take different cases in other contexts, í dag is simply the normal idiomatic way to say today.

Compare:

• í dag = today
• í gær = yesterday
• á morgun = tomorrow

These are best learned as set time expressions.

Literally, it is related to in day, but that is not how you should understand it in normal use.

As a phrase, í dag just means today.

In this sentence, English may naturally translate it as for today:

• Þetta dugir í dag = This will do for today

That extra for is often just what sounds best in English. It does not mean Icelandic has a separate word there for for in this sentence.

Because Icelandic present tense often covers meanings that English may express with either the present or future, depending on context.

So dugir is grammatically present tense, but in context it can mean:

• is enough
• will be enough
• will do

That is very normal. The exact English tense depends on what sounds natural in the situation.

Yes. It is a fully complete sentence.

Structure:

• Þetta = subject
• dugir = verb
• í dag = time expression

It does not need an object. The verb duga often works without one when the meaning is simply that something is sufficient.

Yes. Icelandic word order is flexible, especially when you want to emphasize something.

For example:

• Þetta dugir í dag. = neutral
• Í dag dugir þetta. = Today, this is enough / This will do today

The second version emphasizes today more strongly.

But the original sentence is a very natural, straightforward way to say it.

Þ is pronounced like the th in thin, not like the th in this.

So Þetta begins with the voiceless th sound.

Roughly:

• Þetta ≈ THET-ta

The tt in Icelandic is also pronounced differently from English, but for a beginner, the most important point is:

• þ = th as in thin

In many contexts, yes, the natural English translation might be That’s enough for today, especially if English would normally point to the situation more loosely.

But grammatically, þetta means this.

So the direct sense is still this, even if idiomatic English sometimes uses that in translation.