Sjálfsábyrgðin er há.

Because Icelandic usually puts the definite article on the end of the noun instead of using a separate word like English the.

• sjálfsábyrgð = deductible / excess
• sjálfsábyrgðin = the deductible / the excess

So -in here is the feminine singular nominative form of the suffixed definite article.

It is in the nominative singular.

In this sentence, sjálfsábyrgðin is the subject of the verb er, so nominative is the expected case:

• Sjálfsábyrgðin = subject
• er = is
• há = predicate adjective describing the subject

It is a feminine noun.

You can see that in this sentence from the forms around it:

• the definite article is -in, which fits feminine singular nominative here
• the adjective appears as há, the feminine singular form

So the sentence gives you two clues that the noun is feminine.

Because adjectives in Icelandic agree with the noun they describe in gender, number, and usually case.

Here, sjálfsábyrgðin is:

• feminine
• singular
• nominative

So the adjective must match that:

• masculine: hár
• feminine: há
• neuter: hátt

That is why the sentence uses há.

Because há is a predicate adjective, not an adjective directly in front of the noun.

In Icelandic, adjectives used after vera (to be) are normally in the strong form:

• Sjálfsábyrgðin er há. = The deductible is high.

But when an adjective comes directly before a definite noun, you often get the weak form:

• háa sjálfsábyrgðin = the high deductible

So:

• after er: há
• before the definite noun: háa

This is a very common point for learners.

Er is the 3rd person singular present tense of vera, the verb to be.

So here:

• er = is

Related forms of vera include:

• ég er = I am
• þú ert = you are
• hann/hún/það er = he/she/it is
• við erum = we are

Yes. It is a compound noun, which is very common in Icelandic.

It is made from:

• sjálfs- = self-
• ábyrgð = responsibility / liability

As a compound, sjálfsábyrgð has the specialized insurance meaning deductible or excess.

So even if the parts are recognizable, the full compound has a specific meaning you should learn as a whole word.

Because this is a basic Icelandic subject + verb + complement sentence:

• Sjálfsábyrgðin = subject
• er = verb
• há = complement describing the subject

This is very similar to English:

• The deductible is high.

Icelandic can change word order in some contexts, especially in questions or for emphasis, but this is the normal neutral order for a statement.

Yes, but it changes the meaning.

• Sjálfsábyrgðin er há. = The deductible is high.
  You are talking about a specific deductible.

• Sjálfsábyrgð er há. = A deductible is high / Deductible is high.
  This sounds more general, less tied to one specific policy or situation.

In many real contexts, the definite form is used because you are referring to the deductible in a particular contract, offer, or insurance policy.

The adjective hár / há / hátt changes to match the noun.

For example:

• Kostnaðurinn er hár. = The cost is high.
  masculine singular

• Sjálfsábyrgðin er há. = The deductible is high.
  feminine singular

• Gjaldið er hátt. = The fee is high.
  neuter singular

So learning adjective agreement is very important in Icelandic.

Há is roughly like English how, though not exactly the same.

A useful learner approximation is:

• há ≈ how

Also remember that Icelandic stress normally falls on the first syllable of a word, so há is naturally stressed.

The letter ð is often pronounced somewhat like the th in this.

So in sjálfsábyrgðin, the ð in -ðin is not a d sound. It is closer to a soft voiced th sound.

Learners often confuse ð and þ:

• ð ≈ th in this
• þ ≈ th in thin

That distinction is useful to learn early.

Yes. Icelandic often uses high in the same way English does for prices, fees, costs, and similar amounts.

So using há with a deductible is completely natural, just as English says:

• a high deductible
• high costs
• high fees

So although the core meaning is high, it works idiomatically for amounts and charges too.