Skyrtan verður sléttari eftir að ég strauja hana.

Verður is the 3rd person singular present form of verða.

In this sentence, verða means to become or sometimes will be, depending on how natural the English translation is. So Skyrtan verður sléttari is literally The shirt becomes smoother/flatter, but in natural English it is often translated as The shirt will be smoother.

A useful thing to remember:

• verða + adjective often means become
• verða + infinitive can mean must / have to

So here it does not mean must, because there is no infinitive after it.

Skyrta means shirt.

Skyrtan means the shirt.

Icelandic usually adds the definite article to the end of the noun instead of using a separate word like English the. So:

• skyrta = a shirt / shirt
• skyrtan = the shirt

In this sentence, skyrtan is the subject, and it is in the nominative singular.

Sléttari is the comparative form of sléttur, which means smooth, flat, or in this context less wrinkled.

So:

• sléttur = smooth / flat
• sléttari = smoother / flatter

The ending -ari is a very common way to form the comparative in Icelandic.

Here, sléttari means the shirt becomes more smooth than it was before. It does not need an explicit than phrase, because the comparison is understood: the shirt is smoother after ironing than before.

Because the sentence is talking about a change of state.

• er sléttari = is smoother
• verður sléttari = becomes / will be smoother

Using verður shows that the shirt is not smooth already; it becomes smoother as a result of the ironing.

That makes verður the natural choice here.

Eftir að means after when it introduces a whole clause.

So:

• eftir að ég strauja hana = after I iron it

This is different from eftir used with just a noun phrase, for example:

• eftir vinnu = after work
• eftir mat = after dinner

But when you want after followed by a full clause with a subject and verb, Icelandic uses eftir að.

Because Icelandic often uses the present tense in time clauses referring to the future, especially after words like eftir að.

So eftir að ég strauja hana literally looks like after I iron it, and that is normal. English actually does something similar:

• The shirt will be smoother after I iron it.

English also uses present tense in the after clause, not after I will iron it.

So this is a very natural structure in Icelandic.

Because hana is the accusative form, and the verb strauja takes a direct object.

Here the shirt is the thing being ironed, so it is the object:

• ég strauja hana = I iron it

The pronoun refers back to skyrtan, which is a feminine noun:

• nominative: hún = she / it
• accusative: hana = her / it

So:

• hún would be used as a subject
• hana is used as the object here

That is why ég strauja hana is correct.

Usually yes, when it means to iron something.

Examples:

• ég strauja skyrtuna = I iron the shirt
• ég strauja hana = I iron it

Since ironing is normally done to an item, the verb is typically transitive and takes a direct object in the accusative.

Yes. You can also say:

Eftir að ég strauja hana verður skyrtan sléttari.

That means the same thing: After I iron it, the shirt will be smoother.

This is useful for noticing Icelandic word order:

• In a normal main clause: Skyrtan verður sléttari
• If the sentence begins with the after clause, the finite verb in the main clause still comes early: ... verður skyrtan ...

That is part of Icelandic’s V2 word order in main clauses.

Yes. The adjective is linked to skyrtan through verður, so it describes the subject.

In other words:

• subject: skyrtan
• predicate adjective: sléttari

So the adjective matches the subject grammatically. Learners often just need to remember that after verbs like vera and verða, adjectives describing the subject still agree with that subject.

Yes, the exact English wording depends on context.

Sléttur can mean:

• smooth
• flat
• level
• not wrinkled

With a shirt, the most natural sense is usually smoother or less wrinkled after ironing.

So while flatter is possible literally, smoother is usually the best English choice in this context.