Jag blir irriterad när bussen är sen.

Blir irriterad means become irritated / get irritated, so it focuses on the change of state.

• Jag blir irriterad när bussen är sen = I get irritated when the bus is late.
• Jag är irriterad = I am irritated.

In this sentence, Swedish prefers blir because it describes what happens in that situation: the late bus causes the feeling.

Irriterad is an adjective meaning irritated or annoyed.

The -ad ending is very common in Swedish adjectives that come from verbs or participle-like forms, especially for feelings or states:

• intresserad = interested
• stressad = stressed
• överraskad = surprised
• irriterad = irritated

Here it agrees with jag, but in this form there is no extra ending needed.

In Swedish, bli works as the full verb meaning become / get. You do not add another verb like är with it.

So:

• Jag blir irriterad = I get irritated
• Jag är irriterad = I am irritated

You choose one or the other depending on meaning.

Here när means when.

It introduces a time clause:

• när bussen är sen = when the bus is late

This sentence means that whenever that situation happens, the speaker gets irritated.

It does not literally mean because, although in practice the late bus is also the reason for the irritation.

Bussen is the definite form, meaning the bus.

• en buss = a bus
• bussen = the bus

Swedish usually attaches definiteness to the noun as an ending. Since English says the bus, Swedish uses bussen.

Good question. In this sentence, sen is an adjective describing bussen, so it means late in the sense that the bus itself is late.

• Bussen är sen = The bus is late.

Swedish also has sent, which is often used adverbially:

• Han kommer sent = He arrives late.

So:

• sen = adjective form
• sent = adverb or neuter adjective form

That is why the sentence uses sen, not sent.

It actually does follow Swedish subordinate-clause word order, but this sentence is simple enough that it looks similar to English.

The clause is:

• när bussen är sen

In Swedish subordinate clauses, the subject usually comes before the verb:

• bussen = subject
• är = verb

Compare that with a case involving negation, where the difference is easier to see:

• Main clause: Bussen är inte sen
• Subordinate clause: ... när bussen inte är sen

So the sentence already follows normal Swedish subordinate word order.

Usually it sounds like a general/habitual statement:

• Jag blir irriterad när bussen är sen = I get irritated when the bus is late.

In other words, whenever the bus is late, this is my reaction.

Swedish present tense often covers this kind of general meaning, just like English does.

Yes, and it is very natural. But the meaning shifts slightly.

• bussen är sen = the bus is late
• bussen kommer sent = the bus arrives late / comes late

The first describes the bus's state or situation.
The second focuses more on the actual arrival time.

In everyday speech, both can work, depending on what exactly you want to emphasize.

Not exactly.

• irriterad = irritated, annoyed
• arg = angry

Irriterad is usually milder. If the bus is late, irriterad sounds very natural. Arg would sound stronger, as if the speaker is really angry.

In a normal full sentence, you need jag because Swedish usually requires an explicit subject.

So:

• Jag blir irriterad när bussen är sen. = correct

You could rephrase it in other ways, for example:

• Det är irriterande när bussen är sen. = It is irritating when the bus is late.
• Jag tycker det är irriterande när bussen är sen. = I think it is irritating when the bus is late.

But if you want to say I get irritated, then jag should stay.