Þetta er vitleysa.

A learner-friendly approximation is:

• Þetta → THET-ta or THEH-ta
• er → ehr
• vitleysa → VIT-lay-sa

A few useful pronunciation notes:

• Þ / þ is like th in thing, never like th in this.
• In þetta, the tt is often pronounced with a little breath before it, which is why it can sound a bit like THEH-ta.
• ei in vitleysa sounds like ay in day.
• Icelandic usually stresses the first syllable: ÞET-ta er VIT-ley-sa.

Þetta is a demonstrative pronoun. In this sentence, it means this or this thing / this matter.

Grammatically, it is:

• neuter
• singular
• the subject of the sentence

So in Þetta er vitleysa, þetta is the thing being talked about.

Er is the present tense form of the verb vera, which means to be.

Here it means is.

It is third person singular, because þetta is singular. Compare:

• ég er = I am
• þú ert = you are
• það er = it is

So Þetta er ... is the Icelandic equivalent of This is ...

Vitleysa is a noun, not an adjective.

It is a feminine singular noun meaning something like nonsense, absurdity, or rubbish depending on context.

In this sentence, it works as a predicate noun after er:

• Þetta = subject
• er = verb
• vitleysa = what the subject is being identified as

So the structure is very similar to English This is nonsense.

Because Icelandic has no separate indefinite article.

English says:

• a problem
• an idea
• nonsense

But Icelandic usually just uses the noun by itself when English would use a/an.

So vitleysa can mean:

• nonsense
• a piece of nonsense
• something absurd

depending on context.

If you want the nonsense, Icelandic usually adds the definite article to the end of the noun:

• vitleysan = the nonsense

This is a very common question.

Learners often first meet the demonstrative as þessi, but it changes form depending on gender, number, and case.

Here, þetta is used because it is the neuter singular form.

A useful way to think about it is:

• þessi = a form you often see in tables or with some nouns
• þetta = the form used here for this when the reference is neuter or more general

Also, when Icelandic refers to a whole situation, statement, or idea, þetta is extremely common.

For example, Þetta er vitleysa often means This is nonsense in the sense of What was just said/done is nonsense.

Because after vera (to be), Icelandic normally uses the nominative for a predicate noun.

So here:

• vitleysa = nominative singular

In other contexts, the noun can change form. For example, you may see vitleysu in other cases.

So the short answer is:

• after er in a sentence like this, vitleysa is the expected form

No. This is very normal Icelandic word order for a simple statement.

It follows the basic pattern:

• Subject + Verb + Complement

So:

• Þetta = subject
• er = verb
• vitleysa = complement

That is completely parallel to English This is nonsense.

If you turned it into a question, the order would usually change:

• Er þetta vitleysa? = Is this nonsense?

Yes — very often.

In a sentence like Þetta er vitleysa, þetta usually refers to:

• something someone just said
• an argument
• a claim
• a plan
• a situation

So it does not have to mean a literal physical this object in front of you.

In real use, it often means something like:

• This is nonsense
• That’s nonsense
• What you’re saying is nonsense

depending on the situation.

Yes, it is natural and common.

It sounds like a direct way to dismiss something as absurd, wrong, or ridiculous.

Tone matters a lot:

• said lightly, it can mean That makes no sense
• said strongly, it can sound quite blunt: That’s nonsense

So grammatically it is simple, but pragmatically it can be fairly strong depending on voice and context.

Yes. Bull is another very common word for nonsense.

Both are natural, but they can feel slightly different in tone and style:

• vitleysa = nonsense, absurdity
• bull = nonsense, rubbish, often very colloquial

So:

• Þetta er vitleysa and
• Þetta er bull

are both natural ways to reject something, but bull can sound a bit more casual or more forceful depending on context.