Η εμφάνισή της άλλαξε.

Here is the breakdown:

• Η = the for a feminine singular noun
• εμφάνισή = appearance
  The dictionary form is εμφάνιση
• της = her
  More literally, it is a weak genitive form meaning of her
• άλλαξε = changed
  This comes from the verb αλλάζω

So η εμφάνισή της literally means the appearance of her, which is the normal Greek way to say her appearance.

Because Greek normally uses the definite article with possessive expressions of this type.

So Greek says:

• η εμφάνισή της = literally the appearance of her
• το βιβλίο μου = my book
• η φίλη του = his friend

To an English speaker, the article can feel extra, but in Greek it is the normal structure.

In Greek, these short possessive forms usually come after the noun.

So:

• η εμφάνισή της = her appearance
• το σπίτι μου = my house
• ο αδερφός σου = your brother

This is just a basic difference between English and Greek word order. English puts the possessive before the noun, while Greek often puts this short possessive form after it.

• εμφάνισή is nominative singular, because it is the subject of the verb άλλαξε
• της is genitive singular, because it shows possession

So grammatically:

• η εμφάνισή της = the subject, her appearance
• άλλαξε = the verb, changed

The sentence structure is essentially:

Her appearance + changed

This happens because της is an enclitic word.

The basic noun is εμφάνιση, but when a word like της follows it, Greek spelling often adds an extra accent to the noun:

• η εμφάνιση
• η εμφάνισή της

This does not mean it is a different noun or a different case. It is still the same word. The extra accent is a spelling rule triggered by the following enclitic.

You will see the same kind of thing in other phrases too, such as:

• ο άνθρωπός μου
• ο δάσκαλός της

Άλλαξε is the aorist, 3rd person singular, of αλλάζω.

In this sentence, it usually corresponds to the English simple past:

• changed

The aorist presents the action as a single whole event: her appearance changed.

Compare:

• άλλαξε = changed
• άλλαζε = was changing / used to change
• έχει αλλάξει = has changed

It can do either, depending on whether there is an object.

In this sentence, there is no object, so it is understood intransitively:

• Η εμφάνισή της άλλαξε = her appearance changed

But αλλάζω can also be transitive:

• Άλλαξε το σχέδιο = he/she changed the plan

So the verb itself can work both ways. The rest of the sentence tells you which meaning is intended.

Yes, Greek word order is more flexible than English word order.

The version you have:

• Η εμφάνισή της άλλαξε

is a very natural, neutral sentence.

You could also say:

• Άλλαξε η εμφάνισή της

This is also correct, but it shifts the emphasis a bit more toward the fact that a change happened.

So Greek allows more movement of words than English, although not every order sounds equally natural in every context.

Yes, it can.

Greek pronouns follow grammatical gender, not just natural gender. So της can refer to:

• a female person = her
• a feminine noun referring to a thing or institution = its

For example, if the context were η εταιρεία or η πόλη, then της could mean its in English.

So the exact English translation depends on context.

A common emphatic way is:

• Η δική της εμφάνιση άλλαξε

Here δική της adds emphasis, something like:

• her own appearance changed
• it was her appearance that changed

Without that extra emphasis, Η εμφάνισή της άλλαξε is the normal, neutral way to say it.