Φοβάμαι μην λερώσει η μαγιονέζα το πουκάμισό μου, γι’ αυτό τρώω προσεκτικά στο αυτοκίνητο.

After verbs of fear like φοβάμαι, Greek often uses μη(ν) to introduce the thing someone is afraid might happen.

So φοβάμαι μην λερώσει... means something like:

• I’m afraid that ... might stain ...
• I’m afraid ... will stain ...
• for fear that ...

Here, μην does not simply mean not in the usual sense. In this structure, it is part of a standard pattern used after expressions of fear.

Λερώσει is the 3rd person singular aorist subjunctive form of λερώνω.

In this sentence, it refers to a single possible event: the mayonnaise staining the shirt.

Why the aorist subjunctive here?

• Greek often uses the aorist subjunctive for a possible event viewed as a whole.
• The idea is not it keeps staining or it is staining, but it might stain at some point.

So μην λερώσει is essentially that it might stain.

Because after φοβάμαι μην..., Greek normally uses μην directly, without να.

Compare:

• Θέλω να φάω. = I want to eat.
• Φοβάμαι μην πέσω. = I’m afraid I might fall.

So in this fear construction, μην is doing the job of introducing the subordinate clause. You do not normally say φοβάμαι μην να λερώσει.

Greek uses definite articles much more often than English.

So:

• η μαγιονέζα = the mayonnaise
• το πουκάμισό μου = my shirt

A very important point for English speakers: Greek usually keeps the article even with possessives.

So Greek says:

• το βιβλίο μου = my book
• το σπίτι μας = our house
• το πουκάμισό μου = my shirt

In English, my shirt has no the, but in Greek the article is normal and expected.

Greek word order is more flexible than English word order.

English strongly prefers:

• I’m afraid the mayonnaise will stain my shirt

Greek can say:

• Φοβάμαι μην λερώσει η μαγιονέζα το πουκάμισό μου

Putting η μαγιονέζα after the verb is perfectly natural. The sentence still works because the article η clearly marks it as the subject.

This word order can sound natural because the speaker first presents the feared action, then names what causes it.

A more English-like order would also be possible:

• Φοβάμαι μην η μαγιονέζα λερώσει το πουκάμισό μου

But the version you have is very idiomatic.

Because of the article and case marking.

• η μαγιονέζα is feminine singular nominative, so it is the subject.
• το πουκάμισό μου is the object.

Even though English relies heavily on word order, Greek often gives you grammatical clues through articles and endings.

So here the meaning is:

• the mayonnaise = the thing that might do the staining
• my shirt = the thing that might get stained

This happens because μου is an enclitic.

The word πουκάμισο is stressed early in the word, and when an enclitic like μου follows, Greek often adds a second written accent:

• πουκάμισο
• το πουκάμισό μου

This extra accent helps preserve the correct pronunciation pattern.

You will see the same thing in other phrases such as:

• ο δάσκαλός μου
• το τηλέφωνό σου

So the accent is not random; it follows a regular rule involving enclitics.

Γι’ αυτό is a shortened form of για αυτό and means:

• that’s why
• for this reason
• so

In your sentence, it connects the two ideas:

• I’m afraid the mayonnaise might stain my shirt,
• that’s why I eat carefully in the car.

The apostrophe shows that a vowel has been dropped in the shortened form:

• για αυτό → γι’ αυτό

This contraction is very common in everyday Greek.

Because προσεκτικά is an adverb, and it describes how the person eats.

• τρώω προσεκτικά = I eat carefully

By contrast, προσεκτικός / προσεκτική / προσεκτικό are adjective forms and describe a noun:

• Είμαι προσεκτικός. = I am careful.
• Είναι προσεκτική. = She is careful.

So after a verb like τρώω, you need the adverb:

• προσεκτικά

Στο is a contraction of:

• σε + το = στο

So literally:

• στο αυτοκίνητο = in the car / in the automobile

With τρώω, it means the eating happens while the speaker is in the car.

This is a very common contraction in Greek:

• σε + τον = στον
• σε + τη(ν) = στη(ν)
• σε + το = στο

So τρώω ... στο αυτοκίνητο simply means I eat ... in the car.

Yes. Φοβάμαι μήπως... is also very common and natural.

So these are both possible:

• Φοβάμαι μην λερώσει η μαγιονέζα το πουκάμισό μου.
• Φοβάμαι μήπως λερώσει η μαγιονέζα το πουκάμισό μου.

For many learners, μήπως may feel easier because it often appears in clauses expressing worry, uncertainty, or concern about something happening.

The difference in everyday use is usually small here, and both are idiomatic. If you hear either one, you should understand them the same way in this context.

Because the sentence is talking about a possible single result, not an ongoing action.

• λερώσει focuses on the event as a whole: might stain
• λερώνει would sound more like a general or ongoing action: stains / is staining

Here the speaker fears one accidental moment: a drop of mayonnaise might get on the shirt. That is why the aorist subjunctive λερώσει is the natural choice.