Девушка ждёт трамвай на остановке.

It is in the accusative, but for masculine inanimate nouns, the accusative singular is often identical to the nominative singular.

So:

• трамвай = nominative singular
• трамвай = accusative singular as well

Because ждать takes a direct object, трамвай here is accusative, even though it looks unchanged.

Compare:

• Я вижу трамвай. = I see a tram.
• Я жду трамвай. = I am waiting for a tram.

But with a feminine noun, you would see a visible change:

• Я жду девушку. = I am waiting for the girl.

Because this phrase answers the question where?, not to where?

• на остановке = at the stop / on the stop area → location
• на остановку = to the stop → direction

After на, Russian uses:

• Prepositional case for location: на остановке
• Accusative case for motion toward something: на остановку

So:

• Девушка ждёт трамвай на остановке. = The girl is waiting for the tram at the stop.
• Девушка идёт на остановку. = The girl is going to the stop.

This is largely just the normal Russian idiom.

Russian commonly says:

• на остановке = at the stop
• на вокзале = at the station
• на улице = on the street / outside

Even if English might use at, Russian often uses на in these public-place expressions.

So this is something worth learning as a set phrase:

• ждать автобус на остановке
• стоять на остановке
• встретиться на остановке

Russian has no separate tense form for the English present continuous.

So ждёт can mean:

• waits
• is waiting

Which one sounds best depends on context.

Here, in a normal sentence describing what is happening right now, English usually prefers:

• The girl is waiting for a tram at the stop.

Russian simply uses the present tense:

• ждёт

Yes. In Russian, ждать usually takes its object directly.

English says:

• wait for a tram

Russian says literally more like:

• wait a tram

So:

• ждать трамвай
• ждать автобус
• ждать друга

This is a very common difference between English and Russian. You do not normally add a separate word meaning for here.

Yes. Russian word order is more flexible than English because case endings show the grammatical roles.

The neutral word order here is:

• Девушка ждёт трамвай на остановке.

But you could also say:

• На остановке девушка ждёт трамвай.
• Трамвай девушка ждёт на остановке.

These versions shift the emphasis:

• На остановке... puts the location first
• Трамвай... highlights what she is waiting for

Even though the order changes, the meaning stays basically the same because девушка is the subject and трамвай is the object.

It can mean both, depending on context.

девушка often means:

• girl
• young woman

It can also sometimes be used like young lady in everyday speech.

So the sentence could be understood as:

• The girl is waiting for a tram at the stop.
• The young woman is waiting for a tram at the stop.

Without more context, either may be fine.

It is the prepositional singular form of остановка.

The dictionary form is:

• остановка

After на meaning location, Russian uses the prepositional case:

• на остановке

So the pattern is:

• остановка → basic form
• на остановке → at the stop

This is a very common feminine noun pattern:

• школа → в школе
• улица → на улице
• остановка → на остановке

A learner may want to notice these:

• деву́шка
• ждёт
• трамва́й
• на остано́вке

A few useful pronunciation notes:

• ё in ждёт is always stressed: ждёт
• трамвай has final stress: трамва́й
• остановке is stressed on но́: остано́вке
• In normal writing, Russian often omits the dots on ё, so you may see ждет, but it is still pronounced ждёт

Russian has no articles.

So:

• Девушка can mean a girl, the girl, or sometimes just girl in a general sense
• трамвай can mean a tram or the tram

Context tells you which one is meant.

In this sentence, English could translate it as:

• The girl is waiting for a tram at the stop.
• A girl is waiting for the tram at the stop.
• The girl is waiting for the tram at the stop.

The best choice depends on the situation, not on a special word in Russian.

Yes, it could be either.

Because Russian has no articles, трамвай does not by itself tell you whether it is:

• a tram in general
• the tram that has already been mentioned
• a specific tram known from context

So the sentence is grammatically neutral on that point. Only context makes it clear.

For example:

• If she just wants transportation, English might say a tram
• If both speakers already know which tram she needs, English might say the tram