Ef skuldin væri minni, myndi hún ekki hugsa svona mikið um hana.

Because the sentence describes a hypothetical situation, not a real present fact.

• er = is
• væri = were / would be

In Icelandic, væri is the past subjunctive of vera (to be), and it is commonly used in if-clauses for unreal or imagined situations:

• Ef skuldin er minni... = If the debt is smaller...
  This sounds like a real possibility or factual condition.
• Ef skuldin væri minni... = If the debt were smaller...
  This is hypothetical or contrary-to-fact.

So this sentence is using the same kind of pattern as English If the debt were smaller, ...

Myndi is the conditional form of munu, and here it works like English would.

So:

• myndi hún hugsa = she would think
• myndi hún ekki hugsa = she would not think

This matches the hypothetical if-clause:

• Ef skuldin væri minni = If the debt were smaller
• myndi hún ekki hugsa... = she would not think...

A very common Icelandic pattern is:

• Ef + past subjunctive ..., myndi + infinitive ...

So this sentence is a textbook conditional structure.

Because Icelandic follows the verb-second rule.

In a main clause, the finite verb usually comes in the second position. When the sentence starts with an if-clause, that whole clause takes the first slot, so the finite verb of the main clause comes next:

• Ef skuldin væri minni, myndi hún...

Structure:

1. Ef skuldin væri minni = first element
2. myndi = finite verb in second position
3. hún = subject

If the sentence stood alone without the opening if-clause, you would normally get:

• Hún myndi ekki hugsa svona mikið um hana.

So the word order changes because the sentence begins with the conditional clause.

Skuldin means the debt, while skuld means debt or a debt, depending on context.

The ending -in is the definite article attached to the noun:

• skuld = debt / a debt
• skuldin = the debt

Icelandic usually attaches the to the end of the noun instead of using a separate word like English does.

So skuldin shows that a specific debt is being talked about.

Because Icelandic pronouns agree with the grammatical gender of the noun they refer to.

Skuld is a feminine noun, so when you refer back to it, you use a feminine pronoun:

• skuld = feminine
• hana = her/it in the accusative feminine singular

Even though debt is not a female person, Icelandic still uses the feminine pronoun because the noun is grammatically feminine.

So in this sentence:

• hún = she
• hana = it / her, referring to skuldin

That can feel strange to English speakers, because English uses it for things. Icelandic instead follows grammatical gender.

Hana is accusative singular feminine.

It is accusative because it comes after the preposition um, and um normally takes the accusative case.

So:

• um hana = about it / about her

Here hana refers back to skuldin.

This is a useful pattern to remember:

• hugsa um e-ð / e-n / e-a = to think about something / someone

So the case is not random: the preposition um requires it.

Because the Icelandic verb hugsa usually needs the preposition um when it means think about.

So:

• hugsa um = think about

This works much like English:

• think about it
• hugsa um hana

Without um, the meaning changes or becomes unnatural in this context.

So the full expression to learn is really:

• að hugsa um eitthvað = to think about something

Svona mikið means this much, so much, or in natural English here, so much.

In this sentence:

• ekki hugsa svona mikið um hana = not think about it so much

A rough breakdown:

• svona = like this / this way / this much
• mikið = much / a lot

Together they often mean something like so much in everyday English.

So the sentence is not saying literally in this way much in normal English. The natural translation is:

• she would not think about it so much

Because ekki usually comes before the infinitive or the part of the predicate it negates.

Here the finite verb is myndi, and the infinitive is hugsa:

• myndi hún ekki hugsa...

This is a normal Icelandic order for a conditional sentence with negation.

You can think of it as:

• would she not think...

So ekki is placed before hugsa to negate the action of thinking.

Minni is the comparative form of lítill (small).

So:

• lítill = small
• minni = smaller

It agrees with skuldin:

• skuldin = feminine singular nominative
• minni = comparative adjective matching that noun in the sentence

Because skuldin is the subject and comes after væri, the adjective is describing the subject:

• skuldin væri minni = the debt were smaller

So minni is a predicate adjective linked to skuldin through væri.

Yes. That is a very good way to think about it.

The Icelandic sentence uses a form that corresponds most closely to formal English were in hypothetical statements:

• Ef skuldin væri minni... = If the debt were smaller...

In everyday English, many speakers also say was, but Icelandic clearly marks the hypothetical meaning here with væri.

So if you want the best English comparison for the grammar, were is the closest match.

Yes.

• hún refers to the woman: she
• hana refers to the debt: it, but in feminine form because skuld is feminine

So the sentence contains two feminine references, but they point to different things:

• hún = the female person who is thinking
• hana = the debt she is thinking about

This can be confusing because both are feminine forms. You have to tell them apart from the context.

Yes. Icelandic can rearrange the clauses.

For example, you could say:

• Hún myndi ekki hugsa svona mikið um hana ef skuldin væri minni.

That means the same thing:

• She would not think about it so much if the debt were smaller.

The main difference is word order. When the sentence begins with the if-clause, the next clause has verb-second order:

• Ef ..., myndi hún...

When the main clause comes first, the order is more straightforward:

• Hún myndi... ef ...

Yes:

• Ef = if
• skuldin = the debt
• væri = were
• minni = smaller
• myndi = would
• hún = she
• ekki = not
• hugsa = think
• svona mikið = so much / this much
• um = about
• hana = it / her, referring to the debt

So the structure is:

• If the debt were smaller, would she not think so much about it

In natural English:

• If the debt were smaller, she wouldn’t think about it so much.