Hún græðir mikið.

Hún means she.

In this sentence, it is in the nominative case because it is the subject of the verb: she is the one doing the earning.

It is also singular and feminine.

Græðir is the 3rd person singular present tense of the verb græða.

So:

• hún græðir = she earns / she profits
• hann græðir = he earns / he profits
• það græðir = it earns / it profits

In other words, this is the normal present-tense verb form used with a singular third-person subject.

No. Græða can have several related meanings depending on context, such as:

• earn
• make a profit
• gain
• sometimes heal / cure in other contexts

In Hún græðir mikið, the most natural meaning is usually She earns a lot or She makes a lot of money / profit.

Without more context, learners should usually understand it in the money/profit sense.

Because mikið is not describing a noun here. It is modifying the verb græðir.

So here mikið means a lot / much, not big.

A very common Icelandic pattern is that the neuter singular form of an adjective is used adverbially. That is exactly what is happening here:

• mikill = big / great / much
• mikið = a lot / much

So Hún græðir mikið literally works like She earns much / a lot.

Functionally, it is being used like an adverb, because it modifies the verb græðir.

Its form comes from the adjective mikill, but in this sentence it does not mean that she is big or great. It tells you how much she earns.

So in practice, you can understand mikið here as a lot.

Because mikið is not describing hún.

If a word describes a noun or pronoun directly, Icelandic usually makes it agree in gender, number, and case. But here mikið is not saying anything about she herself. It is saying how much she earns.

So:

• hún = the subject
• græðir = the action
• mikið = how much

That is why you do not get feminine agreement here.

Because Icelandic, like English, can leave the object understood when the meaning is general.

Compare English:

• She earns a lot.

You do not need to say money every time, because it is obvious from the context.

The same is true in Icelandic:

• Hún græðir mikið.

If you want to make the object explicit, you can add one, for example:

• Hún græðir mikla peninga. = She earns a lot of money.

No. This is the most neutral word order:

• Hún = subject
• græðir = verb
• mikið = adverbial expression

So it is a normal Subject–Verb–Adverb sentence.

However, Icelandic often follows a verb-second pattern, so other word orders are possible for emphasis or style. For example:

• Mikið græðir hún.

This is more marked and emphasizes mikið.

But the original sentence is the plain, normal order.

You would usually say:

• Hún græðir ekki mikið.

Here ekki means not.

A useful pattern is:

• Hún græðir mikið. = She earns a lot.
• Hún græðir ekki mikið. = She doesn’t earn much.

You can make a yes/no question by putting the verb first:

• Græðir hún mikið? = Does she earn a lot?

This is a very common Icelandic pattern.

So:

• statement: Hún græðir mikið.
• question: Græðir hún mikið?

No. The finite verb does not change for masculine vs. feminine vs. neuter.

So you get:

• Hann græðir mikið. = He earns a lot.
• Hún græðir mikið. = She earns a lot.
• Það græðir mikið. = It earns a lot.

What matters here is person and number, not gender.

A rough English-friendly guide would be:

• Hún ≈ hoon
• græðir ≈ GRAI-thir
• mikið ≈ MIH-kith

A few helpful points:

• ú in hún is roughly like oo in food
• æ in græðir is roughly like the vowel in fine
• ð is like th in this
• stress in Icelandic normally falls on the first syllable

This is only an approximation, but it is a good starting point for a learner.