Barnen går två och två till skolan på morgonen.

Barnen means the children.

The base word is barn, which is a bit unusual because it can mean both child and children depending on context:

• ett barn = a child
• barn = children
• barnet = the child
• barnen = the children

So the -en here is the definite plural ending.

Because går is the present tense of gå, which means to go or to walk.

• att gå = to go / to walk
• går = go/goes / are going / walk/walks

In Swedish, the verb usually has to be conjugated in a main clause:

• Barnen går till skolan = The children go to school

You would not use the infinitive gå here, just like you would not say The children to go to school in English.

It can suggest both, depending on context.

Gå very often means walk, but in some everyday expressions it can be translated more naturally as go. In this sentence, many learners first understand it as go, but it may also imply that the children are physically walking.

So:

• literal sense: The children walk...
• natural English translation in many contexts: The children go...

The exact nuance depends on the situation.

Två och två means two by two or in pairs.

It is a common Swedish pattern used to show that people or things are grouped:

• en och en = one by one
• två och två = two by two
• tre och tre = three by three

So Barnen går två och två means the children are going in groups of two.

Because number + och + number is a normal Swedish way to express grouping or distribution.

It is very idiomatic and common. English often uses:

• in pairs
• two by two
• one at a time

Swedish can also use other expressions, but två och två is one of the most natural ways to say it.

In Swedish, definiteness is often built into the noun itself as an ending, instead of using a separate word like the.

Here:

• skola = school
• skolan = the school

So till skolan literally means to the school.

But just like in English, go to school can sometimes have a general meaning. Swedish often still uses the definite form in these everyday destination expressions:

• gå till skolan = go to school
• gå till jobbet = go to work
• åka till stan = go into town

So even though skolan literally contains the, the most natural English translation may simply be to school.

Because Swedish usually puts the at the end of the noun as a suffix.

Compare:

• en skola = a school
• skolan = the school

That means Swedish does not need a separate article in most cases. You normally would not say den skolan here, because den skolan means that school or that particular school, which is more specific or contrastive.

På morgonen means in the morning.

This is the normal Swedish expression for a specific time of day in a general recurring sense:

• på morgonen = in the morning
• på eftermiddagen = in the afternoon
• på kvällen = in the evening

Learners sometimes expect i morgonen, but that is not how Swedish says it. For time-of-day expressions like this, på is the usual preposition.

They mean completely different things:

• på morgonen = in the morning
• i morgon = tomorrow

This is a very common thing for learners to mix up because they look similar.

So:

• Barnen går till skolan på morgonen = The children go to school in the morning
• Barnen går till skolan i morgon = The children go to school tomorrow

Yes. This is standard Swedish main-clause word order:

• Barnen = subject
• går = verb
• två och två = adverbial expression
• till skolan = direction
• på morgonen = time

So the sentence follows the usual pattern where the finite verb comes early, typically in second position.

A very common alternative is to start with the time phrase:

• På morgonen går barnen två och två till skolan.

That is also correct. When Swedish starts with something other than the subject, the verb still comes before the subject in the main clause.

Yes, absolutely.

Both are correct:

• Barnen går två och två till skolan på morgonen.
• På morgonen går barnen två och två till skolan.

The difference is mostly emphasis. Starting with på morgonen highlights the time more strongly.

This is a good example of the Swedish V2 rule: in a main clause, the finite verb usually stays in the second position.

For the same reason as with skolan: Swedish usually marks definiteness with an ending.

• morgon = morning
• morgonen = the morning

So på morgonen literally contains the inside the noun. Swedish does not need a separate word like the in front.

Yes, to some extent. Swedish adverbial phrases can often move around.

For example, these are possible:

• Barnen går två och två till skolan på morgonen.
• Barnen går till skolan två och två på morgonen.
• På morgonen går barnen två och två till skolan.

The most natural position depends on what you want to emphasize, but the original sentence is completely normal.

Most naturally, it sounds habitual or general: something the children do as a routine.

That is because på morgonen often suggests a regular time, and the present tense in Swedish is commonly used for habitual actions:

• Barnen går ... på morgonen = The children go ... in the morning / mornings

If you wanted to make it clearly about one specific event, the larger context would usually make that obvious.