Quand le soleil est bas, le pare-brise sale gêne la vue et le rétroviseur ne suffit pas.

Quand means when and introduces a time clause.

In Quand le soleil est bas, it sets the situation for the rest of the sentence: when this happens, the other things happen too.

A native English speaker may expect something like When the sun is low..., and that is exactly the role of quand here.

You could also see lorsque in French, but quand is more common and natural in everyday language.

Because soleil is a masculine noun, and the adjective must agree with it.

• le soleil = masculine singular
• so the adjective is bas = masculine singular

If the noun were feminine, you would use basse instead.

For example:

• la table est basse = the table is low

Here:

• le soleil est bas

After être, French usually uses an adjective to describe the subject.

So:

• le soleil est bas = literally the sun is low

This works just like English:

• The road is narrow
• The sun is low

So bas is a predicate adjective here, placed after the verb est.

Pare-brise is a fixed compound noun, and French writes many compounds with a hyphen.

It comes historically from:

• parer = to ward off, protect against
• brise = breeze, wind

But as a learner, the main thing to know is that pare-brise is simply the normal word for windshield or windscreen, and it is written with a hyphen as one unit.

Because sale usually comes after the noun in French.

So:

• un pare-brise sale = a dirty windshield

This is very common with descriptive adjectives like:

• sale = dirty
• propre = clean
• grand = big
• important = important

Some adjectives often come before the noun, but sale normally comes after.

Sale is an adjective modifying pare-brise.

It agrees with pare-brise, which is masculine singular, so the form is:

• sale

This adjective has the same form in masculine and feminine singular:

• un pare-brise sale
• une vitre sale

In the plural:

• des pare-brises sales
• des vitres sales

Gêne is the third-person singular form of the verb gêner, meaning to bother, hinder, obstruct, interfere with.

So:

• le pare-brise sale gêne la vue means the dirty windshield interferes with vision.

The accent in gêne is part of the spelling of the verb family:

• gêner
• je gêne
• il/elle gêne

It helps mark pronunciation and distinguish the form visually. For learners, it is best to memorize gêner with its accent from the start.

In French, la vue often means vision, visibility, or one’s sight in a general sense.

So gêner la vue is a common way to say that something obstructs visibility. French does not always use a possessive where English might.

Compare:

• Ça gêne la vue. = It obstructs visibility.
• Il s’est lavé les mains. = He washed his hands.

French often prefers the definite article (la, les) when the meaning is obvious from context.

Using le here makes it sound like a specific, understood mirror in the situation, or the mirror as a relevant item in general driving context.

French often uses the definite article where English may also use the for something contextually obvious:

• le volant
• la route
• le rétroviseur

If you said un rétroviseur, it would sound more like a rear-view mirror, introducing one as just any example. But here the sentence is talking about the mirror available to the driver in that situation, so le is more natural.

Rétroviseur means rear-view mirror.

It can refer to:

• the interior rear-view mirror
• sometimes, depending on context, a side mirror

In a driving sentence like this, many learners wonder whether it means one specific mirror. In practice, the singular often refers to the mirror being relied on in the situation. If the sentence wanted to emphasize multiple mirrors, it could say les rétroviseurs.

This is the standard French negation pattern:

• ne
  • verb + pas

Here:

• suffit = is enough / suffices
• ne suffit pas = is not enough / does not suffice

So:

• le rétroviseur ne suffit pas

The verb is suffire:

• je suffis
• tu suffis
• il/elle suffit
• nous suffisons
• vous suffisez
• ils/elles suffisent

In everyday spoken French, the ne is often dropped in casual speech:

• le rétroviseur suffit pas But in correct written French, you keep ne ... pas.

Because the subject is singular:

• le rétroviseur = singular

So the verb must also be singular:

• le rétroviseur suffit
• le rétroviseur ne suffit pas

If the subject were plural, the verb would be plural too:

• les rétroviseurs ne suffisent pas

It is in the present tense.

French often uses the present tense for:

• general truths
• habitual situations
• things that are true whenever the condition happens

That fits this sentence well: it describes what happens when the sun is low.

So even if English might sometimes use a more explanatory form, the French present is perfectly natural here.

The comma separates the introductory time clause from the main clause.

Structure:

• Quand le soleil est bas, = subordinate clause
• le pare-brise sale gêne la vue et le rétroviseur ne suffit pas. = main clause

This punctuation is very common and helps readability, especially when the time clause comes first.

The sentence already has a clear structure:

• le pare-brise sale gêne la vue
• et
• le rétroviseur ne suffit pas

Each part has its own subject and verb, so nothing extra is needed.

French often links two complete clauses with et, just like English:

• X does this, and Y does not do that

So the sentence is balanced and natural as written.