La suola e il tacco sono consumati.

Because the subject is made of two nouns joined by e:

• la suola = the sole
• il tacco = the heel

Together they form a plural subject, so Italian uses the 3rd person plural of essere:

• sono = are

So La suola e il tacco sono consumati literally has the structure The sole and the heel are worn.

This is because suola is feminine, but tacco is masculine.

When Italian has a mixed-gender plural group, the adjective normally takes the masculine plural form.

So:

• la suola = feminine singular
• il tacco = masculine singular
• together = masculine plural
• therefore: consumati

If both nouns were feminine, you would use consumate.

The clearest clue is the article:

• la suola → feminine
• il tacco → masculine

The noun endings also help sometimes:

• -a often suggests feminine: suola
• -o often suggests masculine: tacco

But the article is the safest sign here.

Here consumati means something like:

• worn
• worn down
• worn out

The verb consumare has a broad meaning: to consume, to use up, to wear out.
With parts of a shoe, it usually means they have been damaged by use, especially from friction with the ground.

So in this context, consumati is the natural way to say that the sole and heel are worn down.

Grammatically, consumati is the past participle of consumare, but in this sentence it is functioning very much like an adjective after essere.

So you can think of the pattern as:

• essere + past participle/adjectival form

This is very common in Italian:

• La porta è chiusa = The door is closed
• Le scarpe sono rovinate = The shoes are damaged
• La suola e il tacco sono consumati = The sole and the heel are worn out

For a learner, it is often easiest to understand consumati here as a descriptive word agreeing with the subject.

In Italian, when you join two specific nouns with e, it is very common to give each noun its own article:

• la suola e il tacco

This is the normal, natural way to say the sole and the heel.

Repeating the article helps show that these are two separate things.
English often does the same:

• the sole and the heel

Not in this sentence structure.

Here consumati comes after sono because it is describing the subject in a predicate structure:

• La suola e il tacco sono consumati

That is the normal order.

You could change the word order for emphasis in some contexts:

• Sono consumati la suola e il tacco

But that is less neutral and more marked. For most learners, the standard order to use is:

• subject + verb + adjective/past participle

Yes. Both the verb and consumati would need to agree with the single noun.

Examples:

• La suola è consumata = The sole is worn out
• Il tacco è consumato = The heel is worn out

Notice the agreement:

• la suola → feminine singular → è consumata
• il tacco → masculine singular → è consumato

Not always, but that is the meaning here.

Tacco can refer to:

• the heel of a shoe
• sometimes the heel-shaped part of something

In this sentence, because it appears together with suola, the meaning is clearly the heel of the shoe.

Yes, depending on the nuance you want. For example:

• usurati = worn, worn down
• rovinati = damaged
• logori = worn out, shabby

But consumati is very natural when talking about shoe parts that have been worn down through use.

So La suola e il tacco sono consumati sounds completely normal and idiomatic.