Barnen börjar skolan den elfte september.

Barnen is the definite plural form of barn.

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

A useful thing to notice is that barn has the same form in the indefinite singular and plural. The ending -en here marks definite plural.

Börja is the infinitive form, meaning to begin / to start.

Börjar is the present tense:

• att börja = to begin
• börjar = begin / begins / are beginning

So in this sentence, barnen börjar means the children begin / are starting.

Also, Swedish verbs do not change for person the way English verbs sometimes do. You use the same present-tense form with all subjects:

• jag börjar
• du börjar
• barnen börjar

Because Swedish often uses the definite form where English uses no article.

The expression börja skolan or börja i skolan means to start school. In this kind of idea, skolan often refers to school as an institution or stage of life, not just a physical building.

So:

• börja skolan = start school

Even though English says start school, Swedish idiomatically uses skolan.

This is a standard Swedish way to express a date:

• den
  • ordinal number
    • month

So:

• den elfte september = the eleventh of September / September 11th

Here, elfte is the ordinal form of elva (eleven):

• elva = eleven
• elfte = eleventh

In Swedish, dates are often said with den before an ordinal number:

• den första maj
• den tjugofjärde december
• den elfte september

This den is just part of the normal date pattern. It is not being used the same way as English the in every context, but the translation is often similar.

In less formal writing, Swedish also often uses just the numeral:

• 11 september

But in a fully written-out date, den elfte september is very natural.

Because Swedish normally does not use a preposition here.

English says:

• on September 11th

Swedish simply says:

• den elfte september

So the sentence does not need a word like på before the date.

In Swedish, names of months and days of the week are normally written with a lowercase letter unless they begin the sentence.

So:

• september
• måndag
• tisdag

This is different from English, where September is capitalized.

The sentence follows the basic Swedish statement pattern:

• Barnen = subject
• börjar = verb
• skolan = object/complement
• den elfte september = time expression

So the order is:

subject + verb + object/complement + time

That is very normal in Swedish.

Yes, it can.

You can say:

Den elfte september börjar barnen skolan.

This is still correct, but Swedish then follows the V2 rule, which means the finite verb must stay in the second position.

So after the time expression comes the verb:

• Den elfte september börjar barnen skolan.

Not:

• Den elfte september barnen börjar skolan.

A rough guide is BUR-yar, but that is only approximate.

A few important points:

• j in Swedish sounds like English y
• ö does not sound exactly like English u or o
• the stress is on the first syllable: BÖR-jar

So börjar sounds roughly like:

• BÖR-yar

If you want a more careful approximation:

• the ö is somewhat like the vowel in British English bird, but without copying the English r sound exactly

So the main thing to remember is:

• j = y
• stress on the first syllable
• ö is a special Swedish vowel you will need to get used to hearing and saying