Hún styður mig þegar mér líður illa.

Hún means she. It is the normal nominative singular feminine pronoun, so it is the form used for the subject of the sentence.

• hún = she
• mig = me

The accent in ú is just part of the spelling and pronunciation. In Icelandic, accented vowels are separate vowel sounds, not just decorative marks.

Styður means supports. It comes from the verb styðja, meaning to support.

So:

• að styðja = to support
• ég styð = I support
• hún styður = she supports

This verb changes its stem a bit in the present tense, which is why you get styður rather than something more predictable like styðjar.

Because mig is the accusative form of ég (I / me), and here it is the direct object of styður.

• ég = I
• mig = me

In Hún styður mig, hún is doing the action, and mig is receiving it.

So the grammar matches English:

• She supports me not
• She supports I

Þegar means when here.

It introduces a time clause:

• Hún styður mig = She supports me
• þegar mér líður illa = when I feel bad / when I’m feeling unwell

So the whole sentence means:

• She supports me when I feel bad

In other contexts, þegar can also relate to time in slightly different ways, but when is the natural meaning here.

This is one of the most important things to notice in the sentence.

Mér is the dative form of ég. The expression mér líður uses the dative, not the nominative or accusative.

Forms of ég:

• ég = I
• mig = me (accusative)
• mér = me (dative)
• mín = my / mine-related forms, depending on grammar

In Icelandic, some verbs and expressions require cases that do not match English expectations. The verb líða in the sense of feel / be doing emotionally or physically commonly takes a dative experiencer:

• Mér líður vel = I feel well
• Mér líður illa = I feel bad

So mér is correct because that is the case this expression requires.

Here líður comes from líða, and in this expression it means something like:

• feel
• be feeling
• be doing emotionally/physically

So mér líður illa means:

• I feel bad
• I’m feeling unwell
• I’m not feeling good

This is a very common Icelandic pattern:

• Mér líður vel = I feel good
• Henni líður illa = She feels bad
• Okkur líður vel = We feel good

So when you see líður with a dative pronoun like mér, think of the pattern someone feels a certain way.

Because illa is an adverb, while ill is an adjective.

Here it modifies the verb phrase mér líður:

• illa = badly / poorly / unwell

Compare:

• Hún er ill. = She is bad/evil/mean or ill, depending on context.
  Here ill is an adjective describing hún.
• Mér líður illa. = I feel bad / I feel unwell.
  Here illa is an adverb describing how someone feels.

In English, bad is often used where grammar would suggest badly, but Icelandic uses the adverb form here: illa.

More or less, yes—that is a helpful way to think about the structure.

A literal breakdown is:

• mér = to me / for me
• líður = feels / is feeling
• illa = badly / poorly

So literally it is something like:

• To me, it feels bad or
• I am feeling bad

But the natural English translation is simply:

• I feel bad
• I’m feeling unwell

Literal breakdowns are useful for understanding the grammar, but they are not always the best final translation.

Because that is not how this Icelandic expression works.

With líða in this meaning, Icelandic normally uses:

• a dative pronoun/noun for the person experiencing the feeling
• the verb form líður
• an adverb such as vel or illa

So the correct pattern is:

• Mér líður vel = I feel good
• Mér líður illa = I feel bad

Not:

• ég líð illa ❌

This is one of those structures you should learn as a whole phrase.

The sentence is built very straightforwardly:

• Hún styður mig = main clause
• þegar mér líður illa = subordinate time clause

So the structure is:

• She supports me
  • when I feel bad

The Icelandic word order here is very close to English. The main difference is that inside the þegar clause, the person experiencing the feeling appears as mér because of the dative construction.

Usually styður here would be understood as supports me in an emotional or general sense, especially because it is followed by þegar mér líður illa (when I feel bad).

So the natural interpretation is:

• she helps me
• she is there for me
• she supports me emotionally

The verb styðja can also mean support in other senses, depending on context:

• support a person
• support an idea
• support a team
• support financially

But in this sentence, emotional support is the most likely reading.

Yes. It can refer to either:

• emotional distress
• general discomfort
• physical illness
• feeling miserable overall

Context decides which meaning is intended.

For example:

• If someone is sad or overwhelmed: mér líður illa = I feel bad
• If someone is sick: mér líður illa = I feel unwell / I feel sick

So this sentence can cover both emotional and physical states unless the wider context makes one meaning clearer.

Yes, absolutely. This is a very useful pattern.

With styðja:

• Hún styður mig = She supports me
• Hann styður þig = He supports you
• Þau styðja hana = They support her

With líður:

• Mér líður illa = I feel bad
• Þér líður illa = You feel bad
• Honum líður illa = He feels bad
• Henni líður illa = She feels bad
• Okkur líður illa = We feel bad
• Þeim líður illa = They feel bad

So this sentence gives you two very useful pieces at once:

1. how to say support someone
2. how to say someone feels good/bad

The three most useful things to remember are:

1. styðja takes an object in the accusative

   • mig = me

2. líða in this meaning uses the dative experiencer

   • mér líður = I feel

3. illa is the adverb used with líður

   • mér líður illa = I feel bad

If you remember the sentence as two chunks, it becomes much easier:

• Hún styður mig
• þegar mér líður illa

That is often the best way to learn Icelandic grammar: as patterns inside real sentences.