Утром моя подруга снова села на ту же лавочку и допила кофе.

Утром is the instrumental singular of утро (morning), but here it functions like an adverb meaning in the morning.

This is a very common Russian pattern:

• утром = in the morning
• днём = in the daytime / during the day
• вечером = in the evening
• ночью = at night

So Утром here is not a subject or object. It simply sets the time of the action.

Моя means my, and it agrees with подруга in:

• gender: feminine
• number: singular
• case: nominative

Since подруга is feminine singular, the possessive pronoun must also be feminine singular:

• мой друг = my male friend
• моя подруга = my female friend

Russian often includes possessives where English might or might not. In this sentence, моя подруга is simply my friend.

In the past tense, Russian verbs agree with the subject in gender and number.

The subject is моя подруга, which is feminine singular, so the verbs take feminine singular past endings:

• сел = he sat down
• села = she sat down
• допил = he finished drinking
• допила = she finished drinking

That is why both verbs end in -а.

Because сесть / села means to sit down — a movement into a seated position.

By contrast, сидеть / сидела means to be sitting — the state of already sitting.

So:

• села на лавочку = sat down on the bench
• сидела на лавочке = was sitting on the bench

In this sentence, the action is about her taking a seat, not about the state of sitting.

This is the classic Russian difference between direction and location.

With на:

• на + accusative = motion onto/to something
• на + prepositional = location on something

So:

• села на лавочку = sat down onto the bench
• сидела на лавочке = was sitting on the bench

Because села describes motion into position, Russian uses the accusative: лавочку.

Ту же means that same.

It is made from:

• ту = accusative feminine singular of та (that)
• же = a particle meaning same / exactly / the very

Together:

• ту же лавочку = the same bench

All parts must agree with лавочку, which is feminine singular accusative:

• ту же книгу = the same book
• того же человека = the same person
• то же место = the same place

So ту же is not redundant. It is the normal way to say the same with a demonstrative.

Лавочку is the accusative singular of лавочка.

Here it is accusative because it is the destination of the action after села на.

About the word itself:

• лавочка usually means bench
• it is a diminutive form, so it can sound a little more natural, familiar, or concrete than лавка

Be careful: лавка can also mean small shop in some contexts, so лавочка is often the clearer word for a bench.

Forms:

• nominative: лавочка
• accusative: лавочку
• prepositional: на лавочке

In this sentence, снова means again.

Very roughly:

• снова = again
• опять = again, often very common in speech, sometimes with an emotional tone like again!
• ещё раз = one more time / again

In many contexts, снова and опять are interchangeable:

• снова пришёл
• опять пришёл = came again

But снова can sound a little more neutral or literary, while опять is very common in everyday speech and can sometimes sound annoyed depending on context.

Here, снова simply means she did this again.

Допила comes from допить, which means to finish drinking something that was already being drunk.

So:

• пила кофе = was drinking coffee / drank coffee
• выпила кофе = drank the coffee up
• допила кофе = finished the remaining coffee

The prefix до- often gives the idea of finishing something to the end.

In this sentence, допила кофе suggests that some coffee was already there, and she finished it.

Кофе is the direct object of допила, so it is in the accusative.

But кофе is one of those Russian nouns whose form usually does not change in the singular, so nominative and accusative look the same:

• кофе (nominative)
• кофе (accusative)

Traditionally, кофе is treated as masculine in standard Russian, even though it ends in -е:

• горячий кофе
• вкусный кофе

In modern informal speech, some speakers also use neuter agreement, but learners should generally stick with masculine.

Because the subject is the same for both verbs.

Russian, like English, often avoids repeating the subject when it is understood:

• Моя подруга села на лавочку и допила кофе.

This means:

• My friend sat down on the bench and finished her coffee.

Repeating моя подруга again would sound unnecessary unless you wanted special emphasis.

Russian word order is fairly flexible, but changing it changes the focus or emphasis.

The neutral order here is:

• Утром моя подруга снова села на ту же лавочку и допила кофе.

Possible variations:

• Моя подруга утром снова села на ту же лавочку и допила кофе.
• Снова утром моя подруга села на ту же лавочку и допила кофе.
• На ту же лавочку моя подруга снова села утром и допила кофе.

All of these are possible in the right context, but they highlight different parts of the sentence.

The original version sounds natural and starts by setting the time: In the morning...

Yes, but it would mean something slightly different.

Compare:

• села на ту же лавочку = sat down on the same bench
  
  • motion, so accusative
• сидела на той же лавочке = was sitting on the same bench
  
  • location, so prepositional

So if the verb changed from села to сидела, then на той же лавочке would be correct.

This is a very important pattern in Russian:

• motion toward a place → accusative
• being in a place → prepositional

Because Russian has no articles like a and the.

Whether something is definite or indefinite is understood from context, word order, or words like этот, тот, какой-то, etc.

Here, definiteness is already clear from:

• ту же лавочку = that same bench
• кофе = understood from context as the coffee she had

So Russian does not need separate words for the.