Non toccare il fornello, è ancora caldo.

Because this is a negative command addressed to you in the informal singular.

In Italian, the negative imperative for tu is formed with:

non + infinitive

So:

• toccare = to touch
• non toccare = don’t touch

This is different from affirmative commands:

• Tocca! = Touch it!
• Non toccare! = Don’t touch!

That pattern is very common:

• Non parlare! = Don’t speak!
• Non entrare! = Don’t come in!
• Non correre! = Don’t run!

Fornello usually means a burner on a stove, or sometimes the hob/ring/hotplate depending on context and regional usage.

So in this sentence, il fornello is the hot part of the stove that you should not touch.

Related words:

• forno = oven
• cucina = kitchen, or sometimes stove/cooker depending on context
• fornello = burner / stove ring / hob

A native English translation may vary depending on the kind of stove being imagined.

Italian usually uses an article where English sometimes does not.

So il fornello literally means the burner.

Even if English might say Don’t touch the stove burner or just Don’t touch the burner, Italian naturally includes the article here.

This is very normal:

• Chiudi la porta. = Close the door.
• Lava le mani. = Wash your hands.
• Accendi la luce. = Turn on the light.

Because è is the verb is from essere.

• è = is
• e = and

The accent is important because it distinguishes two different words:

• è ancora caldo = it is still hot
• e ancora caldo would be incorrect here

So the accent is not optional.

The subject is understood: it refers to il fornello.

Italian often omits subject pronouns when they are clear from context. So instead of saying:

• Il fornello è ancora caldo

the sentence simply says:

• è ancora caldo

because everyone understands that the speaker still means the burner.

In English, you usually need it:

• It’s still hot.

In Italian, leaving the subject out is completely normal.

Because caldo agrees with fornello, which is a masculine singular noun.

Agreement works like this:

• fornello = masculine singular
• caldo = masculine singular adjective

If the noun were feminine, the adjective would change:

• La pentola è ancora calda. = The pot is still hot.

If plural:

• I fornelli sono ancora caldi. = The burners are still hot.
• Le pentole sono ancora calde. = The pots are still hot.

Here ancora means still.

So:

• è ancora caldo = it is still hot

This tells you the burner was hot before and continues to be hot now.

Be careful: ancora can also mean again, depending on context.

Examples:

• È ancora caldo. = It is still hot.
• Leggilo ancora. = Read it again.

So the exact meaning depends on the sentence.

Italian often links short related clauses with a comma, especially in speech or simple warnings.

So:

• Non toccare il fornello, è ancora caldo.

literally feels like:

• Don’t touch the burner, it’s still hot.

English can do this too in informal speech, though in careful writing English often prefers:

• Don’t touch the burner; it’s still hot.
• Don’t touch the burner because it’s still hot.

Italian does not need perché here, though you could say:

• Non toccare il fornello perché è ancora caldo.

That version is also correct, just a bit more explicit.

Yes, if the object is already clear from context.

• Non toccare il fornello. = Don’t touch the burner.
• Non toccarlo. = Don’t touch it.

Here lo means it and replaces il fornello.

With the negative tu command, the pronoun can go before the infinitive:

• Non lo toccare.
• Non toccarlo.

Both are possible, though Non toccarlo is very common and natural.

The sentence uses the informal singular command, talking to one person you address as tu.

Other versions would be:

• Non tocchi il fornello, è ancora caldo. = formal singular (Lei)
• Non toccate il fornello, è ancora caldo. = plural (voi)

So the negative imperative changes depending on who is being addressed.

Quick comparison:

• tu: Non toccare
• Lei: Non tocchi
• voi: Non toccate

Because cc before a, o, u has a hard k sound.

So toccare is pronounced roughly:

tohk-KAH-reh

The stress falls on -ca-:

• tocCAre

Useful comparison:

• toccare = hard k sound
• cena = soft ch sound
• città = soft ch sound
• cosa = hard k sound

A simple rule:

• c before a, o, u = hard sound
• c before e, i = soft sound

With cc, the same basic pattern applies.

Yes, very natural.

It sounds like a normal warning someone might say in a kitchen or around a hot surface:

• Non toccare il fornello, è ancora caldo.

It is clear, idiomatic, and completely standard. Depending on context, a speaker might also say:

• Non toccarlo, è ancora caldo.
• Attento, il fornello è ancora caldo.
• Non toccare, scotta. = Don’t touch, it burns / it’s burning hot.

But the original sentence is perfectly normal Italian.