Þegar börnin rífast, bið ég þau að hlusta betur á hvort annað.

This is because Icelandic usually follows a verb-second pattern in main clauses.

When the sentence starts with the subordinate clause Þegar börnin rífast = When the children argue, that whole clause takes the first position. Then the finite verb of the main clause comes next:

• Þegar börnin rífast, bið ég þau ...

So the order is:

• subordinate clause
• finite verb: bið
• subject: ég

If you started without the þegar clause, you would normally say:

• Ég bið þau að hlusta betur á hvort annað.

Þegar means when here. It introduces a time clause:

• Þegar börnin rífast = When the children argue

It tells you under what circumstance the speaker asks them to listen better.

Depending on context, þegar can sometimes also mean as / whenever, but when is the most natural basic meaning here.

Börnin means the children.

It breaks down like this:

• barn = child
• börn = children
• börnin = the children

So this is the definite plural form of barn.

In this sentence, börnin is the subject of rífast, so it is in the nominative.

The ending -st often marks what is called the middle voice in Icelandic. Many -st verbs have meanings that are not directly predictable from the basic verb, so it is best to learn them as full vocabulary items.

Here:

• að rífast = to argue, quarrel, bicker

So you should think of rífast as its own verb meaning argue, not as a literal reflexive like argue oneself.

In the sentence:

• börnin rífast = the children are arguing

Bið is the 1st person singular present tense of að biðja = to ask / request / pray.

So:

• ég bið = I ask

In this sentence:

• bið ég þau ... = I ask them ...

Be careful not to confuse að biðja with English to bid. In Icelandic, biðja is the normal verb for ask in this kind of structure.

Þau refers back to börnin.

Because barn is a neuter noun, the matching plural pronoun is þau:

• börnin = the children
• þau = they / them, referring to those children

Here it means them, because it is the object of bið:

• bið ég þau ... = I ask them ...

So functionally it is accusative, although for this pronoun the nominative and accusative forms are the same: þau.

This is a very common Icelandic pattern:

• biðja einhvern að + infinitive

It means:

• to ask someone to do something

In your sentence:

• bið ég þau að hlusta
• literally: I ask them to listen

So the structure is:

• bið = ask
• þau = someone
• að hlusta = to listen

This is one of the most useful verb patterns to learn as a chunk.

Betur means better. It is the comparative form of vel = well.

So:

• hlusta vel = listen well
• hlusta betur = listen better

In natural English, this often comes out as:

• listen better
• listen more carefully

So að hlusta betur means to listen better / more carefully.

Because the verb hlusta normally takes á:

• hlusta á einhvern = listen to someone

So if you want to say listen to each other, Icelandic keeps that á:

• hlusta á hvort annað

This is just how the verb is built. You cannot usually drop the preposition here.

Hvort annað means each other.

This is the Icelandic reciprocal expression used when two or more people do something to one another.

Here it refers back to börnin / þau, which are neuter plural, so the form used is:

• hvort annað

You can think of the whole phrase as a set expression:

• á hvort annað = to each other / to one another

So the full phrase:

• hlusta betur á hvort annað
• means listen better to each other

The comma separates the initial subordinate clause from the main clause:

• Þegar börnin rífast, = subordinate clause
• bið ég þau ... = main clause

This is normal Icelandic punctuation, especially when a clause like Þegar ... comes first.

It helps show the structure clearly:

• When the children argue, I ask them ...

Yes. For example, you could also say:

• Ég bið þau að hlusta betur á hvort annað þegar börnin rífast.

But that version is a bit less natural because börnin and þau refer to the same people, and separating them can make the sentence feel slightly heavier.

The original sentence is very natural because it sets up the situation first:

• When the children argue, I ask them ...

That ordering is common and clear in Icelandic.