Ela mudou a direção.

Mudou is the simple past (also called the preterite) of mudar = to change.

So:

• eu mudei = I changed
• você/ele/ela mudou = you/he/she changed

In Ela mudou a direção, mudou means she changed.

Here, a is the definite article meaning the.

So:

• a direção = the direction

This a is not a preposition here. It is just the feminine singular article, because direção is a feminine noun.

In Portuguese, every noun has a grammatical gender, usually masculine or feminine.
Direção is simply a feminine noun, so it takes feminine words with it:

• a direção
• esta direção
• nova direção

This grammatical gender does not mean the thing itself is female. It is just part of how the noun behaves in Portuguese grammar.

Yes. Portuguese often leaves out the subject pronoun when it is clear from context.

So both are possible:

• Ela mudou a direção.
• Mudou a direção.

The first is more explicit: She changed the direction.
The second is more natural in many contexts if everyone already knows who did it.

In Brazilian Portuguese, mudou is pronounced roughly like moo-DOH.

A few details:

• mu sounds like moo
• dou has the stress
• the ending ou in Brazilian Portuguese often sounds like a simple oh

So mudou is approximately moo-DOH.

A rough Brazilian Portuguese pronunciation is:

jee-reh-SOWN

A few important points:

• di often sounds like jee in many Brazilian accents
• the stress is on the last syllable: -ção
• -ção is a very common ending, pronounced roughly like sown with a nasal sound

So the whole word is approximately jee-reh-SOWN.

The ã in -ção shows that the vowel is nasal.

So direção is not pronounced like a plain a sound at the end.
Instead, the ending has a nasal quality: -ção.

This ending appears in many Portuguese nouns:

• informação
• situação
• tradução
• direção

It is a very useful pattern to learn early.

Both patterns exist, but they are used a little differently.

• mudar a direção = to change the direction
• mudar de direção = to change direction / to change directions

So:

• Ela mudou a direção do carro. = She changed the car’s direction.
• Ela mudou de direção. = She changed direction.

Your sentence uses the direct object pattern: mudou a direção.

Yes. Direção can have more than one meaning depending on context, such as:

• direction in space
• guidance
• management / administration
• the principal’s office / school administration in some contexts

For example:

• A direção da escola = the school administration / management
• seguir a direção correta = follow the correct direction

In your sentence, it depends on context, but learners should know the word is not limited to road or movement direction.

The sentence is shorter and more general: Ela mudou a direção.

If you want to say the direction of something, Portuguese usually adds de:

• Ela mudou a direção do carro. = She changed the direction of the car.
• Ela mudou a direção da câmera. = She changed the direction of the camera.

So your sentence is complete on its own, but Portuguese can add more information if needed.

The normal order is:

• Ela = subject
• mudou = verb
• a direção = object

So Ela mudou a direção is the standard word order.

But Portuguese can sometimes vary word order for style or context. For example:

• Mudou a direção. = omitted subject
• A direção, ela mudou. = marked emphasis, less neutral

For everyday use, the basic order Ela mudou a direção is the safest choice.

Yes, depending on context.

Most often, ela means she and refers to a female person. But it can also refer back to a previously mentioned feminine noun, especially in more careful or written language.

So in many cases:

• ela = she

But grammatically, it can also mean it, referring to something feminine that was already mentioned.

The dictionary form is mudar, meaning to change.

So when you look up mudou, you should look for mudar.

A few related forms:

• mudar = to change
• mudando = changing
• mudança = change

This is a very common verb in Portuguese.