Sur la piste cyclable, Marie utilise la sonnette quand un chien traverse devant son vélo.

French normally uses sur for being on a road, path, lane, or other surface. So sur la piste cyclable is the natural way to say that Marie is on the bike path.

Using dans would suggest being physically inside something, which does not fit well here.

Examples:

• sur la route = on the road
• sur le trottoir = on the sidewalk
• sur la piste cyclable = on the bike path

Piste cyclable is a common term for a bike path or cycle track.

Literally:

• piste = track, path, lane
• cyclable = suitable for cycling / for bicycles

So la piste cyclable is the designated place for bikes. In some contexts, English might say bike lane, cycle lane, or bike path, depending on the exact road layout.

The phrase Sur la piste cyclable has been moved to the front to set the scene. The comma helps separate that introductory location phrase from the main clause.

A more neutral order would be:

• Marie utilise la sonnette sur la piste cyclable quand un chien traverse devant son vélo.

But French often puts time or place information first for emphasis or style:

• Sur la piste cyclable, Marie...
• Le matin, Marie...
• En hiver, Marie...

Because the verb has to be conjugated to match the subject Marie.

The infinitive is utiliser = to use.

With Marie = she, you need the third-person singular present form:

• j’utilise
• tu utilises
• il / elle utilise
• nous utilisons
• vous utilisez
• ils / elles utilisent

So Marie utilise means Marie uses / is using.

French often uses the definite article where English might use a possessive or a more general form.

Here, la sonnette refers to the specific bell involved in the situation, most naturally the bell on her bike. It is understood from context, so French uses the bell rather than a bell.

Compare:

• Marie utilise la sonnette = Marie uses the bell
• Marie utilise une sonnette = Marie uses a bell
  This sounds more like you are introducing one bell out of many, or talking about the type of object.

So la sonnette is the more natural choice here.

Yes, in many contexts you could use sonner.

For example:

• Marie sonne quand un chien traverse...

That means Marie rings the bell.

The difference is mostly one of wording:

• utilise la sonnette = uses the bell
• sonne = rings

Utilise la sonnette is slightly more explicit and descriptive. Sonne is often more direct and idiomatic when the focus is specifically on making the bell ring.

Here quand can be understood as when or whenever, depending on context.

Because the sentence is in the present tense, it often suggests a habitual or repeated action:

• whenever a dog crosses in front of her bike, Marie uses the bell

So this is not necessarily one single event. It can describe what she generally does in that situation.

French often uses the present tense this way to describe routines, habits, or typical reactions.

Because the dog is being introduced as a nonspecific dog, not a particular dog already known to the listener.

• un chien = a dog
• le chien = the dog

So un chien traverse means this could be any dog. If the dog had already been mentioned, or if both speaker and listener knew which dog was meant, le chien would be more likely.

Traverse is the present tense of traverser, which means to cross.

French often uses traverser as a direct verb:

• traverser la rue = to cross the street
• traverser le parc = to cross the park

In this sentence, un chien traverse devant son vélo means the dog crosses in front of her bike. The phrase devant son vélo tells you where the crossing happens.

So even if English might structure this a little differently, the French is natural: the dog is crossing, and it is doing so in front of her bike.

Because devant is already a preposition meaning in front of. It can directly introduce a noun phrase.

So you say:

• devant la maison = in front of the house
• devant moi = in front of me
• devant son vélo = in front of her bike

You do not need an extra de here.

Because French possessive adjectives agree with the thing possessed, not with the owner.

Marie is female, but vélo is a masculine noun, so you use:

• son vélo

Compare:

• son vélo = her bike / his bike
• sa bicyclette = her bicycle / his bicycle

So:

• Marie et son vélo is correct
• Marie et sa bicyclette is also correct because bicyclette is feminine

The possessive form tells you the gender of the noun, not the gender of Marie.

The present tense here is probably being used to describe a general situation, a habit, or a typical reaction.

So the sentence sounds like:

• this is what Marie does when this kind of thing happens

If you wanted to describe one specific past event, you would normally use past tenses instead, for example:

• Sur la piste cyclable, Marie a utilisé la sonnette quand un chien a traversé devant son vélo.

That would refer to one completed incident in the past.

In the original sentence, the present makes it feel more like a routine or a scene being described live.

Yes, in many cases lorsque could replace quand:

• Marie utilise la sonnette lorsque un chien traverse...

However, in actual French, this would become:

• Marie utilise la sonnette lorsqu’un chien traverse...

Lorsque is a bit more formal or literary than quand. In everyday speech, quand is usually more common and more natural.

So:

• quand = common, everyday
• lorsque = slightly more formal

Both can mean when in this kind of sentence.