Ho il pollice sporco di vernice.

Yes. Ho is the first-person singular present of avere: I have.

In this sentence, Italian uses avere in a way that is very common with body parts:

• Ho il pollice sporco di vernice = literally I have the thumb dirty with paint

English usually prefers My thumb is dirty with paint, but Italian often says it with avere instead.

So ho is the main verb here, not an auxiliary.

With body parts, Italian usually uses the definite article when the owner is already clear.

So Italian prefers:

• Ho il pollice sporco di vernice

rather than:

• Ho il mio pollice sporco di vernice

Because the I in ho already tells you whose thumb it is.

You can say:

• Il mio pollice è sporco di vernice

but that sounds a little more explicit and less natural in many everyday situations. The version with il is the normal, idiomatic one.

It means thumb specifically.

Italian distinguishes between:

• dito = finger
• pollice = thumb

So pollice is not a general word for any finger. It refers to the thumb.

Because sporco agrees with pollice.

• pollice is masculine singular
• so the adjective must also be masculine singular: sporco

Agreement works like this:

• il pollice sporco = masculine singular
• la mano sporca = feminine singular
• i pollici sporchi = masculine plural
• le mani sporche = feminine plural

So sporco is chosen because it matches pollice.

Because in Italian, adjectives often come after the noun.

So:

• il pollice sporco = the dirty thumb

That is the normal order here.

Sometimes Italian adjectives can come before the noun, but with a descriptive adjective like sporco, the position after the noun is the usual one.

After sporco, Italian commonly uses di to say dirty with / covered in / stained with a substance.

So:

• sporco di vernice
• sporco di fango
• sporco di sangue

This is the natural pattern.

Using con here would sound unnatural in standard Italian. Con usually means with in the sense of accompaniment or instrument, but after sporco, di is what Italian normally wants.

Vernice can mean several related things depending on context, such as:

• paint
• varnish
• lacquer
• sometimes polish

In this sentence, the intended meaning is most naturally paint.

So even though vernice is a broader word than just English paint, the translation paint is perfectly natural here.

Yes, absolutely. That sentence is correct.

It means the same basic thing, but the structure is different:

• Ho il pollice sporco di vernice = literally I have the thumb dirty with paint
• Il mio pollice è sporco di vernice = My thumb is dirty with paint

The first version is especially idiomatic in Italian when talking about body parts and their condition. The second version is also correct, but it feels a bit more direct and explicit.

Grammatically, yes, but it would usually mean something slightly different.

• Ho il pollice sporco di vernice = the normal way to say my thumb is dirty with paint
• Ho un pollice sporco di vernice = I have a thumb dirty with paint

Using un sounds more indefinite, as if you are identifying one thumb among others, or introducing it as new information in a special context.

In ordinary speech, if you are talking about your own thumb, il pollice is much more natural.

No. Here ho is a full main verb meaning I have.

Compare:

• Ho il pollice sporco di vernice = I have my thumb dirty with paint
• Ho mangiato = I have eaten

In ho mangiato, ho is an auxiliary helping form the past tense. In ho il pollice sporco di vernice, ho carries its own meaning: have.

Yes, and that is also very natural, but it means something a little different.

• Ho il pollice sporco di vernice focuses on the current state
• Mi sono sporcato il pollice di vernice focuses on the action/result: I got my thumb dirty with paint

So both are good, but they are not identical in nuance.

A simple pronunciation guide is:

o il POL-li-che SPOR-co di ver-NI-che

More carefully in IPA:

/ɔ il ˈpɔllitʃe ˈspɔrko di verˈnitʃe/

A few helpful points:

• ho is pronounced just like o; the h is silent
• pollice has the stress on POL
• vernice has the stress on NI
• ce at the end of pollice and vernice sounds like che in English chess

Yes, very common.

Italian often says have + definite article + body part + adjective:

• Ho le mani fredde = My hands are cold
• Ha gli occhi chiusi = His/Her eyes are closed
• Abbiamo la faccia rossa = Our face is red

So Ho il pollice sporco di vernice fits a very normal and useful pattern.