Όταν αργεί το λεωφορείο, προσπαθώ να κρατάω την ψυχραιμία μου και να μην εκνευρίζομαι.

Όταν means when. It introduces a time clause:

• Όταν αργεί το λεωφορείο = When the bus is late

In Greek, όταν is very commonly used with the present tense to talk about things that happen repeatedly or generally, not just one single event.

So here the sense is:

• Whenever the bus is late, I try...

Because Greek often uses the present tense after όταν when talking about repeated or usual situations.

So:

• Όταν αργεί το λεωφορείο literally looks like When the bus is being late
• but in natural English it means When/Whenever the bus is late

The present tense here gives a general, habitual meaning.

Both are possible.

Greek word order is more flexible than English. The version in the sentence:

• αργεί το λεωφορείο

is completely natural and can sound slightly more fluid in context.

You could also say:

• Όταν το λεωφορείο αργεί, ...

with basically the same meaning.

So this is mainly a matter of word order flexibility, not a change in meaning.

Here αργεί means is late.

The verb is αργώ, which can mean:

• to be late
• to delay
• to take a long time

In this sentence:

• Το λεωφορείο αργεί = The bus is late

So it describes the bus not arriving on time.

Προσπαθώ means I try. Very often in Greek, after verbs like try, want, can, must, Greek uses να + verb.

So:

• προσπαθώ να κρατάω... = I try to keep...
• να μην εκνευρίζομαι = not to get irritated / not to become irritated

You can think of να here as the usual way Greek introduces a dependent verb after I try, I want, I hope, and so on.

Because after προσπαθώ the second verb normally appears in a να-clause.

So Greek says:

• προσπαθώ να κρατάω... literally something like
• I try that I keep...

But in normal English we translate it simply as:

• I try to keep...

Without να, the sentence would be ungrammatical here.

This is a very useful aspect question.

Greek often distinguishes between:

• imperfective forms: ongoing, repeated, habitual
• perfective forms: single whole action, often seen as one event or achievement

Here:

• να κρατάω την ψυχραιμία μου suggests trying to remain calm / keep calm as an ongoing state
• να κρατήσω την ψυχραιμία μου would sound more like to manage to keep my calm in a particular instance

Since the whole sentence is about a repeated situation (when the bus is late) and an ongoing effort, κρατάω fits very naturally.

Literally it means:

• κρατάω = I keep / hold
• την ψυχραιμία μου = my calm / my composure

So the whole phrase means:

• I keep my calm
• more naturally: I keep my cool, I stay calm, or I keep my composure

It is a common expression in Greek.

Greek uses the definite article much more often than English.

So even though English says:

• my calm or more naturally
• my composure

Greek says:

• την ψυχραιμία μου literally
• the calmness my

This is normal Greek structure:

• article + noun + possessive pronoun

Examples:

• το βιβλίο μου = my book
• τη γνώμη μου = my opinion
• την ψυχραιμία μου = my composure

Μου means my, but grammatically it is the weak possessive form, historically related to of me.

So:

• την ψυχραιμία μου = my composure

This pattern is extremely common in Greek:

• ο φίλος μου = my friend
• το σπίτι μου = my house
• την υπομονή μου = my patience

Because the sentence has two coordinated actions after προσπαθώ:

• να κρατάω την ψυχραιμία μου
• και να μην εκνευρίζομαι

Greek usually repeats να in this structure. It is the most natural way to connect the two infinitive-like clauses.

So the structure is:

• I try [to keep my calm] and [to not get irritated]

In Greek:

• προσπαθώ να ... και να ...

Because after να, Greek normally uses μη(ν) for negation, not δεν.

Compare:

• εκνευρίζομαι = I get irritated / I become irritated
• δεν εκνευρίζομαι = I am not getting irritated / I do not get irritated
• να μην εκνευρίζομαι = not to get irritated

So:

• δεν is used for ordinary statement negation
• μην is used in contexts like να, commands, wishes, and similar structures

That is why να μην εκνευρίζομαι is correct.

Εκνευρίζομαι means I get irritated, I get annoyed, or I become upset/irritated.

The -ομαι ending shows it is in the middle/passive form. In Modern Greek, many verbs with this ending are translated actively in English.

So although it looks passive, it often just has an ordinary active meaning in English:

• εκνευρίζω κάποιον = I irritate someone
• εκνευρίζομαι = I get irritated / I become irritated

This is a very common Greek verb pattern.

Usually not to get irritated fits best here.

Because εκνευρίζομαι often describes the process or tendency of becoming irritated, it works well in a repeated-situation sentence:

• When the bus is late, I try... not to get irritated

If you translated it as not to be irritated, that can also work in some contexts, but not to get irritated is often the more natural nuance here.

Yes. The sentence describes a repeated or typical reaction.

Several things show that:

• Όταν
  • present tense
• αργεί
• προσπαθώ
• κρατάω
• εκνευρίζομαι

Together they give the meaning of something like:

• Whenever the bus is late, I try to stay calm and not get irritated.

So this is not mainly about one single event, but about what the speaker generally does in that situation.

Yes. Both are acceptable.

• κρατάω is very common in everyday speech
• κρατώ is a shorter variant and can sound a bit more formal or concise, depending on context

So these are both possible:

• προσπαθώ να κρατάω την ψυχραιμία μου
• προσπαθώ να κρατώ την ψυχραιμία μου

The meaning is the same.

Yes, that would also be natural, but it is a slightly different expression.

• κρατάω την ψυχραιμία μου = I keep my composure / keep my cool
• παραμένω ψύχραιμος / ψύχραιμη = I remain calm

The original sentence sounds very idiomatic and natural. It emphasizes maintaining self-control in an annoying situation.