La voiture rouge est dans le garage, et ses freins sont efficaces.

La is the feminine singular definite article, meaning the.

French nouns have grammatical gender, and voiture (car) is feminine. So:

• la voiture = the car
• not le voiture

You usually need an article in French where English sometimes uses one and sometimes does not.

In French, most adjectives come after the noun they describe. So:

• une voiture rouge = a red car

That is different from English, where adjectives usually come before the noun.

A small number of common adjectives often come before the noun, but rouge is not one of them.

Because rouge is describing voiture, which is singular.

Agreement rules:

• singular noun → singular adjective
• plural noun → plural adjective

So:

• la voiture rouge = the red car
• les voitures rouges = the red cars

Here, there is only one car, so rouge stays singular.

Est is the third-person singular form of the verb être (to be).

So:

• elle est = it/she is

In La voiture rouge est dans le garage, est means is:

• The red car is in the garage

It matches the subject la voiture rouge, which is singular.

Dans means in or inside, and le garage means the garage.

So:

• dans = in
• le garage = the garage
• dans le garage = in the garage

Garage is a masculine noun, so it takes le in the singular.

Because garage is a masculine noun in French.

So:

• le garage = the garage
• un garage = a garage

Even if a word looks similar to English, its gender in French must simply be learned with the noun.

Et means and.

It joins the two parts of the sentence:

1. La voiture rouge est dans le garage
2. ses freins sont efficaces

So the whole sentence says two things about the same car:

• where it is
• and what its brakes are like

Ses freins means its brakes or her brakes, depending on context. Here it means its brakes, referring to the car.

French often uses a possessive adjective where English does too:

• ses freins = its brakes

If you said les freins, that would just mean the brakes, without clearly showing they belong to the car.

Because ses agrees with the thing possessed, not with the owner.

The owner here is la voiture (feminine singular), but that does not control the form of the possessive. The possessed noun is freins, which is plural.

So:

• son frein = its brake / his brake / her brake (singular masculine noun)
• sa roue = its wheel / his wheel / her wheel (singular feminine noun)
• ses freins = its brakes / his brakes / her brakes (plural noun)

That is an important difference from English.

Because a car normally has more than one brake, and the sentence is talking about the brakes as a set.

So:

• le frein = the brake
• les freins = the brakes

Here:

• ses freins = its brakes

Because the subject of the second clause is ses freins, which is plural.

So both the verb and the adjective must agree with that plural subject:

• ses freins sont efficaces = its brakes are effective

Compare:

• Le frein est efficace = The brake is effective
• Les freins sont efficaces = The brakes are effective

Because efficaces describes freins, which is plural.

Agreement:

• singular: efficace
• plural: efficaces

So:

• un frein efficace = an effective brake
• des freins efficaces = effective brakes

The extra -s marks the plural in writing.

It can mean all three: his, her, or its.

French possessive adjectives do not change according to the natural gender of the owner. They change according to the gender and number of the thing possessed.

So ses freins could mean:

• his brakes
• her brakes
• its brakes

You understand which one is meant from context. Here, because the sentence is about the car, the natural English translation is its brakes.

A simple approximate pronunciation is:

La voiture rouge est dans le garage, et ses freins sont efficaces.
lah vwah-tyur roozh eh dahn luh gah-razh, ay say franh sohn ay-fee-kahs

A few notes:

• voiture is tricky; the vwah- sound is important.
• rouge ends with a soft zh sound.
• dans has a nasal vowel.
• In careful speech, est is often pronounced eh here.
• freins also has a nasal vowel.
• The final -s in efficaces is normally silent.

Yes. Efficace / efficaces is a very common French adjective meaning effective or efficient, depending on context.

In this sentence:

• ses freins sont efficaces means the brakes work well

So it sounds natural and idiomatic in French.