Sjefen ber oss lese referatet før møtet i morgen.

Because Norwegian usually puts the definite article at the end of the noun instead of using a separate word before it.

• sjef = a boss

• sjefen = the boss

• et referat = a summary / a set of minutes

• referatet = the summary / the minutes

• et møte = a meeting
• møtet = the meeting

The ending changes with the noun’s gender:

• many masculine nouns take -en
• many neuter nouns take -et

So Sjefen already means the boss all by itself.

Ber is the present tense of å be, which often means to ask or to request.

Some useful forms are:

• å be = to ask
• ber = asks / ask
• ba = asked
• bedt = asked / requested

In this sentence, ber means the boss is asking or requesting something.

Because oss is the object form of we.

• vi = we → used as the subject
• oss = us → used as the object

Here, sjefen is the subject, because the boss is doing the asking.
Oss is the object, because we are the ones being asked.

Compare:

• Vi leser referatet. = We read the minutes.
• Sjefen ber oss lese referatet. = The boss asks us to read the minutes.

After be in the pattern be + someone + infinitive, Norwegian normally uses the infinitive without å.

So:

• Sjefen ber oss lese referatet.

This works like:

• Jeg ba ham komme. = I asked him to come.
• Hun ber meg vente. = She asks me to wait.

By itself, the infinitive is å lese. But after ber oss, the å is normally left out.

Yes, you can also hear be noen om å gjøre noe.

So these are both possible:

• Sjefen ber oss lese referatet.
• Sjefen ber oss om å lese referatet.

The version without om å is very common and compact.
The version with om å can sound a little more explicit.

A useful distinction is:

• be om noe = ask for something
• be noen om å gjøre noe = ask someone to do something

Referat usually means a written summary of what was said, very often meeting minutes.

So depending on context, it can be translated as:

• the minutes
• the summary
• the report

One thing that often surprises English speakers: Norwegian uses the singular noun referat, while English often says minutes, which is plural.

So:

• referatet = the minutes

even though the Norwegian form is singular.

Før means before.

In this sentence, it introduces a noun phrase:

• før møtet i morgen = before the meeting tomorrow

It can also introduce a whole clause:

• før vi går = before we leave

Also, don’t confuse før with for:

• før = before
• for = for
• for can also mean too in some contexts

Norwegian often uses the present tense together with a time expression instead of a separate future form.

That means a word or phrase like i morgen often does the job of showing future time.

For example:

• Vi reiser i morgen. = We are leaving tomorrow.
• Møtet er i morgen. = The meeting is tomorrow.

In your sentence, the future idea comes from i morgen, not from a special future verb form.

In this sentence, the most natural reading is that i morgen goes with møtet:

• møtet i morgen = the meeting tomorrow / tomorrow’s meeting

So the sentence is understood as asking us to read the minutes before tomorrow’s meeting.

If you wanted to make it clearer that the asking happens tomorrow, you would usually move i morgen earlier in the sentence, for example:

• I morgen ber sjefen oss lese referatet før møtet.

Word placement helps show what the time expression belongs to.

The basic structure is:

• Sjefen = subject
• ber = finite verb
• oss = object
• lese referatet = infinitive phrase
• før møtet i morgen = time/prepositional phrase

So the pattern is roughly:

Subject + verb + object + infinitive phrase + adverbial

This is also a normal Norwegian main clause, where the finite verb comes early in the sentence.

If you move another element to the front, Norwegian still keeps the finite verb in second position:

• I morgen ber sjefen oss lese referatet før møtet.
• Før møtet i morgen ber sjefen oss lese referatet.

That verb-second pattern is a very important part of Norwegian word order.