Ворона летела низко над дорогой.

Because ворона is a grammatically feminine noun, and in the past tense Russian verbs agree with the subject in gender and number.

• masculine: летел
• feminine: летела
• neuter: летело
• plural: летели

So:

• ворона летела = the crow was flying

Even if you are not thinking about a specifically female crow, the noun ворона is grammatically feminine, so the verb must be feminine too.

Here летела is the past tense of the imperfective verb лететь, so it usually suggests an ongoing action or a scene in progress.

So in context it often feels like:

• was flying
• flew (in a descriptive, non-completed sense)

In this sentence, English was flying low over the road is often the best match, because the Russian sentence sounds like it is describing what was happening, not emphasizing a completed result.

Compare:

• Ворона летела низко над дорогой. = The crow was flying low over the road.
• Ворона пролетела над дорогой. = The crow flew over the road / flew across above the road, with more sense of completion.

Because низко is an adverb, and it describes how the crow was flying.

• низко = low / at a low height
• низкая = low (feminine adjective)

In this sentence, we need a word modifying the verb летела, so the adverb is correct:

• летела низко = was flying low

If you used низкая, it would describe a noun instead:

• низкая машина = a low car
• низкая стена = a low wall

So:

• низко describes the action
• низкая describes a thing

After над in this meaning, Russian normally uses the instrumental case.

The noun is:

• nominative: дорога = road
• instrumental: дорогой

So:

• над дорогой = over the road / above the road

This is a very common pattern:

• над домом = over the house
• над рекой = over the river
• над городом = over the city

So дорогой is not an adjective here. It is the noun дорога in the instrumental singular.

Над means over, above, or up over something.

In this sentence:

• над дорогой = over the road

It gives the spatial relationship: the crow was flying in the air above the road.

A useful comparison:

• над дорогой = over/above the road
• по дороге = along the road
• через дорогу = across the road

So the sentence is not saying the crow was flying along the road, but above it.

Ворона is in the nominative case because it is the subject of the sentence — the one doing the action.

• ворона = crow
• ворона летела = the crow was flying

This is the dictionary form of the noun.

So the basic structure is:

• Ворона = subject
• летела = verb
• низко = adverb
• над дорогой = prepositional phrase describing location

No, Russian word order is fairly flexible. The sentence Ворона летела низко над дорогой is a neutral, natural order.

It roughly goes:

• subject: Ворона
• verb: летела
• adverb: низко
• location phrase: над дорогой

You could change the order for emphasis, for example:

• Низко над дорогой летела ворона.
• Над дорогой ворона летела низко.

These all can mean basically the same thing, but the focus shifts slightly. The original sentence is the most straightforward and neutral.

No. Russian has no articles like the or a/an.

So ворона can mean:

• a crow
• the crow

Which one sounds best depends on context.

The same is true for дорога:

• дорогой can correspond to a road or the road in English, depending on the situation.

English forces you to choose an article, but Russian usually leaves that information to context.

Yes. Лететь means to fly or sometimes to be flying, and it is used for movement through the air.

It works for:

• birds
• planes
• insects
• anything flying through space

For a bird like a crow, лететь is exactly the natural verb.

It is different from verbs of going on foot or by vehicle, such as:

• идти = go on foot
• ехать = go by transport
• лететь = fly

So Ворона летела is the normal way to say The crow was flying.