Il retro del foglio è bianco.

Il is the masculine singular definite article, meaning the.

It is used here because retro is a masculine singular noun: il retro = the back / the reverse side.

So:

• il retro = the back side
• il foglio = the sheet of paper

English often uses the the same way, but in Italian you always need the article with nouns like this.

In this sentence, retro means the back, the reverse side, or the back side of something.

So il retro del foglio means the back of the sheet.

A useful distinction:

• retro = the reverse side of an object
• dietro = behind, at the back of something, as an adverb or preposition

For example:

• il retro della pagina = the back of the page
• dietro la porta = behind the door

So here retro is the correct word because we are talking about one side of the paper.

Del is a contraction of di + il.

• di = of
• il = the
• di + il = del

So:

• il retro del foglio = the back of the sheet

This is very common in Italian. Other similar combinations are:

• della = di + la
• dello = di + lo
• dei = di + i
• degli = di + gli
• delle = di + le

Because grammatical gender in Italian is a property of the noun itself, not something you can always predict from real-world meaning.

Foglio is simply a masculine noun:

• il foglio
• plural: i fogli

Because it is masculine, the article is il, not la.

Also note that -o often marks masculine singular nouns, though not always.

Adjectives in Italian usually agree with the noun they describe in gender and number.

Here, bianco describes il retro, not il foglio.

Since retro is masculine singular, the adjective must also be masculine singular:

• il retro è bianco
• la pagina è bianca
• i fogli sono bianchi
• le pagine sono bianche

So the agreement is with retro, which is masculine singular.

Yes, very different.

• è with an accent means is
• e without an accent means and

So in this sentence:

• Il retro del foglio è bianco = The back of the sheet is white

If you wrote e instead, it would be incorrect here.

The accent is important because it distinguishes two different words.

Yes, that is also natural, but it means the same idea in a slightly different structure.

Compare:

• Il retro del foglio è bianco = The back of the sheet is white
• Il foglio è bianco sul retro = The sheet is white on the back

Both are correct. The original sentence focuses specifically on the back side as the subject.

Italian often uses retro by itself when talking about the reverse side of something, without needing an extra word like side.

So instead of saying something like the back side of the sheet, Italian can simply say:

• il retro del foglio

That is a normal and compact way to express the idea.

If you want, Italian can also use expressions like:

• la parte posteriore
• il lato posteriore

But these are usually more formal, technical, or less natural in an everyday sentence like this one.

Usually, foglio means sheet, especially a sheet of paper.

Depending on context, it can refer to:

• a sheet of paper
• a page-like sheet
• a thin flat sheet of some material

In this sentence, most learners will naturally understand foglio as sheet of paper.

Foglio is pronounced roughly like FOHL-lyo, not like an English g sound.

A few pronunciation points:

• gli in many words is a special Italian sound, similar to ly but not exactly the same
• the stress is on the first syllable: FÒ-glio
• retro is RÈ-tro
• bianco is BIAN-co

So the whole sentence is approximately:

eel REH-tro del FOHL-lyo eh BYAN-ko

That is only an approximation, but it helps an English speaker get close.

Yes. It follows a very common pattern:

subject + essere + adjective

Here:

• Il retro del foglio = subject
• è = is
• bianco = adjective

This is a basic and very common structure in Italian, just like in English:

• La casa è grande
• Il tavolo è pulito
• Il retro del foglio è bianco

Grammatically, yes:

• il retro → i retri
• del foglio → dei fogli
• è bianco → sono bianchi

So the full plural would be:

I retri dei fogli sono bianchi.

That said, learners should know that some plurals are less common in everyday conversation than the singular form, depending on context. But grammatically this is correct.