Jeg blev skuffet, fordi min kollega svigtede mig og glemte at sende dokumentet.

Blev skuffet means became disappointed or was disappointed with a focus on the change of state.

• jeg blev skuffet = I became disappointed / I was disappointed
• jeg var skuffet = I was disappointed

In many contexts, both can translate naturally into English as I was disappointed, but Danish often uses blev when something happened that caused the feeling.

So in this sentence, blev fits well because the speaker’s disappointment was a result of what the colleague did.

The sentence is in the past tense.

Here are the past-tense verbs:

• blev = past tense of blive
• svigtede = past tense of svigte
• glemte = past tense of glemme

So the whole sentence describes something that happened in the past.

Here skuffet is used as a past participle/adjective, not as a plural adjective.

In jeg blev skuffet, the pattern is:

• blive + past participle

Examples:

• jeg blev overrasket = I was surprised
• hun blev irriteret = she became irritated
• vi blev skuffede = we became disappointed

If the subject were plural, you would often see -e:

• vi blev skuffede

But with jeg, the singular form skuffet is correct.

Fordi means because and introduces a subordinate clause.

After fordi, Danish normally keeps the subject before the verb:

• fordi min kollega svigtede mig
• literally: because my colleague failed me

So you get:

• min kollega = subject
• svigtede = verb

This is different from main-clause inversion, where the verb can come before the subject.

A useful comparison:

• Min kollega svigtede mig.
• Jeg blev skuffet, fordi min kollega svigtede mig.

After fordi, that normal subject-verb order stays in place.

Svigte means something like:

• to let someone down
• to fail someone
• to betray someone in some contexts

In this sentence, min kollega svigtede mig suggests more than just a small mistake. It often carries an emotional sense: the colleague did not do what the speaker trusted or expected them to do.

So svigte is often stronger than simply glemme.

They are related, but not exactly the same.

• svigtede mig gives the speaker’s emotional interpretation: my colleague let me down.
• glemte at sende dokumentet gives the specific action that caused it: they forgot to send the document.

So the sentence moves from:

1. the emotional result,
2. to the reason,
3. to the concrete event.

That makes the sentence feel natural and expressive.

Because mig is the object form of the pronoun.

Compare:

• jeg = I
• mig = me

In min kollega svigtede mig, the colleague is doing the action, and me is receiving the action. So Danish uses mig.

A quick comparison:

• Jeg svigtede ham. = I let him down.
• Han svigtede mig. = He let me down.

Because glemme is commonly followed by an infinitive with at when you mean forget to do something.

Pattern:

• glemme at + infinitive

Examples:

• Jeg glemte at ringe. = I forgot to call.
• Hun glemte at betale. = She forgot to pay.
• Min kollega glemte at sende dokumentet. = My colleague forgot to send the document.

This is very similar to English forgot to send.

Dokumentet is the definite form and means the document.

In Danish, the definite article is often attached to the end of the noun:

• et dokument = a document
• dokumentet = the document

Since the sentence refers to a specific document, Danish uses the definite form dokumentet.

In Danish, when you use a possessive like min, din, hans, vores, etc., the noun usually stays in its indefinite form.

So:

• min kollega = my colleague
• not min kollegaen

Compare:

• kollegaen = the colleague
• min kollega = my colleague

You generally do not combine a possessive with the suffixed definite ending.

Yes, you can, but it changes the nuance.

Your original sentence:

• Jeg blev skuffet, fordi min kollega svigtede mig og glemte at sende dokumentet.

This presents the events in a simple past narrative.

Your alternative:

• Jeg var skuffet, fordi min kollega havde svigtet mig og glemt at sende dokumentet.

This uses past perfect (havde svigtet, havde glemt or shared havde) and makes the colleague’s actions feel more clearly earlier than the speaker’s emotional state.

So:

• simple past = straightforward storytelling
• past perfect = emphasizes that one past event happened before another past situation

Both are grammatical, but the original is more direct and natural in many everyday contexts.

Because og is linking two verbs with the same subject:

• min kollega svigtede mig
• (min kollega) glemte at sende dokumentet

The subject min kollega applies to both verbs, so Danish normally just uses og without an extra comma there.

The comma you do see is before fordi, where the sentence moves into a subordinate clause.

Yes, Danish allows some reordering, but it changes the emphasis.

For example:

• Fordi min kollega svigtede mig og glemte at sende dokumentet, blev jeg skuffet.

This version puts the reason first. It is perfectly natural.

Notice what happens in the main clause after that fronted subordinate clause:

• blev jeg skuffet
• verb before subject

That is standard Danish V2 word order in the main clause.

So both are correct:

• Jeg blev skuffet, fordi ...
• Fordi ..., blev jeg skuffet.

The first is usually the more neutral, straightforward version.