Η μπογιά άργησε να στεγνώσει, γι’ αυτό άφησα το πινέλο μέσα στο νερό και δεν άγγιξα τον τοίχο.

Yes. Μπογιά is a feminine noun in Greek, so it takes the feminine article η in the nominative singular.

Greek nouns have grammatical gender, and the article has to agree with the noun:

• η μπογιά = the paint
• η shows feminine singular nominative

This is grammatical gender, not biological gender. Many inanimate things in Greek are masculine, feminine, or neuter simply because that is how the noun is classified.

This is a very common Greek pattern:

αργώ + να + verb

It means:

• to be slow to do something
• to take a long time to do something

So άργησε να στεγνώσει means that the paint took a long time to dry.

Breaking it down:

• άργησε = it was slow / it took a while
• να στεγνώσει = to dry

So the whole idea is not literally just it was late, but more naturally it was slow to dry or it took a long time to dry.

Because after να, Greek normally uses the subjunctive, not the ordinary indicative form.

Here:

• στεγνώσει is the aorist subjunctive
• στεγνώνει would be present indicative
• στέγνωσε would be aorist indicative

After να, Greek chooses aspect:

• να στεγνώνει would suggest an ongoing/repeated process
• να στεγνώσει presents the action as a whole, with focus on completion

In this sentence, the point is that the paint was slow to get dry, so the aorist subjunctive στεγνώσει is the natural choice.

Yes. Γι’ αυτό is a very common contracted form of για αυτό.

In this sentence it means:

• therefore
• that’s why
• so

So it connects the first clause to the result:

• the paint was slow to dry,
• so / that’s why I left the brush in the water.

The apostrophe shows that a vowel has been dropped:

• για αυτό → γι’ αυτό

Both forms exist, but γι’ αυτό is extremely common in normal writing.

Because Greek often omits subject pronouns when they are not needed.

The verb endings already show the person:

• άφησα = I left
• δεν άγγιξα = I did not touch

So Greek does not need εγώ unless the speaker wants emphasis or contrast.

For example:

• Άφησα το πινέλο... = I left the brush...
• Εγώ άφησα το πινέλο... = I left the brush... (more emphatic)

This is one of the big differences from English.

They are in the aorist, which is the usual Greek tense for a single completed action in the past.

Here the speaker is describing whole events:

• άφησα = I left
• δεν άγγιξα = I didn’t touch

The focus is not on duration or repetition, but on what happened as complete facts.

If the speaker wanted to express an ongoing or repeated past action, Greek would use the imperfect:

• άφηνα = I was leaving / I used to leave
• άγγιζα = I was touching / I used to touch

So the aorist is the right choice for this kind of short narrative sequence.

Because the nouns have different genders, and Greek articles must agree with gender, number, and case.

• πινέλο is neuter
• τοίχος is masculine

Also, both nouns are direct objects here, so they are in the accusative.

That gives:

• το πινέλο = the brush
  
  • neuter singular accusative
  • same form as nominative
• τον τοίχο = the wall
  
  • masculine singular accusative

Notice the noun change:

• nominative: ο τοίχος
• accusative: τον τοίχο

So this is article + noun agreement plus normal case marking.

Μέσα στο νερό means in the water or more literally inside the water.

• μέσα = inside
• στο νερό = in the water

Using μέσα adds emphasis that the brush was actually left immersed / put in the water, not just near it or associated with it.

Compare:

• άφησα το πινέλο στο νερό = I left the brush in the water
• άφησα το πινέλο μέσα στο νερό = I left the brush down in / immersed in the water

In many contexts both work, but μέσα makes the image more explicit.

Because στο is the standard contraction of:

σε + το → στο

This happens very often in Greek:

• σε το → στο
• σε τη(ν) → στη(ν)
• σε τον → στον
• σε τα → στα

So:

• μέσα στο νερό = inside in the water

This is completely normal and not optional in standard modern usage.

Because δεν is used to negate indicative verbs, including ordinary past-tense statements.

Here:

• δεν άγγιξα = I did not touch

By contrast, μη(ν) is used mainly with:

• the subjunctive
• commands
• certain non-indicative structures

For example:

• να μην αγγίξω = that I not touch / not to touch
• μην αγγίζεις = don’t touch

So in a normal past statement like this one, δεν is the correct negative.

Greek word order is more flexible than English, because verb endings and case endings already show a lot of grammatical information.

The sentence as given sounds natural and neutral:

• Η μπογιά άργησε να στεγνώσει, γι’ αυτό άφησα το πινέλο μέσα στο νερό και δεν άγγιξα τον τοίχο.

But parts could be moved for emphasis. For example:

• Γι’ αυτό άφησα το πινέλο μέσα στο νερό...
• Τον τοίχο δεν άγγιξα.
  This puts extra emphasis on the wall

So the given order is normal, but not the only possible one.

Sometimes yes, but they are not always interchangeable.

• μπογιά is the everyday word for paint, especially as a substance used for painting surfaces
• χρώμα primarily means color

In some contexts χρώμα can also mean paint, especially in broader or more technical usage, but in a sentence about wet paint drying on a wall, μπογιά is very natural.

So here η μπογιά is exactly the kind of word a native speaker would expect.

The apostrophe marks elision, meaning a sound has been omitted.

The full form is:

• για αυτό

In fast, natural usage, this often becomes:

• γι’ αυτό

So the apostrophe shows that the final vowel of για has dropped before the following vowel.

You will see this kind of spelling in several common Greek expressions, especially in everyday writing.