Hon var frustrerad över att bussen var sen igen, men hon försökte ändå behålla lugnet.

Because there are two separate clauses, and each clause needs its own verb:

• Hon var frustrerad ... = She was frustrated ...
• ... att bussen var sen igen = ... that the bus was late again

So the first var describes hon, and the second var describes bussen.

This is a very common Swedish structure.

• frustrerad = frustrated
• över = over/about
• att = that / to

So frustrerad över att bussen var sen igen literally means something like frustrated over that the bus was late again.

In natural English, we would usually say frustrated that the bus was late again or frustrated about the bus being late again. Swedish often uses över att after adjectives and feelings in this kind of sentence.

No. Here sen means late.

So:

• Bussen var sen = The bus was late

This is a common word that can confuse English speakers because it looks a bit like since, but it has nothing to do with that meaning here.

Also note:

• sen can also mean later in other contexts
• but in this sentence it clearly means late

Igen means again, and in Swedish it often comes late in the clause.

• bussen var sen igen = the bus was late again

That word order is very natural in Swedish. English can also put again near the end, so this part matches English fairly well.

Ändå means still, nevertheless, or all the same.

So:

• men hon försökte ändå behålla lugnet = but she still / nevertheless tried to keep calm

It shows contrast: she was frustrated, but despite that, she tried to stay calm.

This is because of normal Swedish word order in a main clause.

In a basic main clause, Swedish often has:

• subject + finite verb + sentence adverb

Here:

• hon = subject
• försökte = finite verb
• ändå = adverb

So:

• hon försökte ändå ...

This is very typical Swedish word order.

Because Swedish normally requires an explicit subject in each clause.

You cannot usually leave it out the way English sometimes does in coordinated phrases.

So Swedish says:

• Hon var frustrerad ..., men hon försökte ändå ...

Even though English might sometimes shorten this to ..., but still tried ..., Swedish normally keeps hon.

Försökte is the past tense of försöka.

• försöka = to try
• försökte = tried

So:

• hon försökte = she tried

This matches the past-time narration of the rest of the sentence.

Because the fixed expression is behålla lugnet, which literally means keep the calm but naturally means keep calm or remain calm.

• lugn = calm
• lugnet = the calm

Swedish often uses the definite form in idiomatic expressions like this. So behålla lugnet is the normal phrase to learn.

Yes, very common.

It is used when someone tries not to get upset, angry, or panicked.

Examples:

• Försök behålla lugnet. = Try to stay calm.
• Hon behöll lugnet under mötet. = She kept calm during the meeting.

So in your sentence, it sounds very natural.

Here att introduces a subordinate clause:

• att bussen var sen igen = that the bus was late again

It works like English that, although English often leaves that out. Swedish is more likely to keep att in this kind of sentence.

So Swedish prefers:

• frustrerad över att bussen var sen igen

rather than dropping att.

Yes, in this sentence men simply means but.

It links two contrasting ideas:

• she was frustrated
• but she still tried to remain calm

So men works exactly as you would expect here.

Because it agrees with hon, which is a common-gender singular person, and in this position the basic form frustrerad is used.

Compare:

• Han var frustrerad. = He was frustrated.
• Hon var frustrerad. = She was frustrated.
• De var frustrerade. = They were frustrated.

The plural form would be frustrerade, but with hon the singular form frustrerad is correct.

Yes, but it would change the style a little.

• hon försökte ändå behålla lugnet = very natural, compact
• hon försökte trots det behålla lugnet = she tried despite that to keep calm

Both are possible, but ändå is shorter and more idiomatic in everyday Swedish here.

It has two main parts joined by men:

1. Hon var frustrerad över att bussen var sen igen
2. men hon försökte ändå behålla lugnet

Inside the first part, there is also a subordinate clause:

• att bussen var sen igen

So the sentence is:

• main clause
• subordinate clause inside it
• then another main clause after men

This is a very typical Swedish sentence pattern.