La tomaia è scollata.

Because tomaia is a feminine singular noun in Italian.
So it takes:

• la = the (feminine singular)
• è = is
• scollata = feminine singular adjective/past participle

Everything agrees with tomaia.

Tomaia is a noun. In shoe-related language, it refers to the upper part of a shoe.

Its basic pattern is:

• singular: la tomaia
• plural: le tomaie

So if you were talking about more than one, you would say Le tomaie sono scollate.

Because it agrees with the feminine singular noun tomaia.

Italian adjectives and many past participles must agree in gender and number with the noun they describe.

Here is the pattern:

• masculine singular: scollato
• feminine singular: scollata
• masculine plural: scollati
• feminine plural: scollate

Since tomaia is feminine singular, the correct form is scollata.

It can be understood as a past participle used adjectivally.

In a sentence like La tomaia è scollata, it functions like an adjective meaning that the upper is in a certain condition or state.

This is very common in Italian. English does the same thing in sentences like:

• The door is closed
• The shoe is damaged

So scollata describes the state of la tomaia.

The accent distinguishes è meaning is from e meaning and.

So:

• è = is
• e = and

This is an important spelling difference in Italian.

A simple pronunciation guide is:

la toh-MAI-ah eh skohl-LAH-tah

A few notes:

• tomaia has the stress on mai
• è sounds like eh
• sc before o is a hard sk sound, so scollata begins like sko-

Yes, and that version can actually be very natural depending on what you want to express.

The difference is roughly:

• La tomaia è scollata = the upper is unglued / detached / in that condition
• La tomaia si è scollata = the upper came unglued

So:

• è scollata focuses on the state
• si è scollata focuses more on the event or change

Both are possible, but they are not exactly identical.

Yes. In other contexts, scollato often means low-cut or décolleté, especially for clothing.

For example:

• un vestito scollato = a low-cut dress

So context matters. With tomaia, the meaning will be determined by the shoe context, not the clothing one.

Italian uses definite articles more often than English does.
So la tomaia is completely normal.

Leaving out the article would usually sound unnatural here unless you were using a special style such as:

• labels
• headlines
• technical notes
• product specifications

In an ordinary sentence, La tomaia è scollata is the standard form.

Yes, but La tomaia è scollata is the most neutral and standard order.

You might also hear:

• È scollata la tomaia

That version can sound more marked or context-driven, as if you are emphasizing scollata or answering a question about what part is detached.

For learners, the normal pattern to remember is:

subject + verb + adjective

The plural is:

Le tomaie sono scollate.

Notice how everything changes to plural:

• la → le
• è → sono
• scollata → scollate

This is a good example of agreement in Italian.

Yes. È is the present tense of essere.

So the sentence is describing a present state:

• La tomaia è scollata = the upper is detached / unglued

It is not a completed action tense like si è scollata, which uses the present perfect.

The form you would usually look up is scollato or the verb scollare.

That is because dictionaries typically list:

• adjectives in the masculine singular form
• verbs in the infinitive form

So if you do not find scollata, try searching for scollato or scollare.