Мой друг берёт письмо со стола.

Because друг is a masculine noun, and the possessive adjective мой has to agree with it in gender, number, and case.

Here, друг is:

• masculine
• singular
• nominative case (the subject)

So the correct form is мой.

Compare:

• мой друг = my male friend
• моя книга = my book
• моё письмо = my letter

Russian has no articles, so there is no direct equivalent of the or a/an.

That means:

• друг can mean a friend or the friend
• письмо can mean a letter or the letter
• стол can mean a table or the table

The exact meaning depends on context, not on a separate word.

Because друг is the subject of the sentence, and subjects are normally in the nominative case.

In Мой друг берёт письмо со стола:

• мой друг = the person doing the action
• therefore it stays in the nominative

If друг had a different role, its form might change:

• Я вижу друга = I see my friend (accusative/genitive-looking form)
• Я говорю с другом = I am speaking with my friend (instrumental)

Yes, письмо is in the accusative case here, because it is the direct object of берёт.

But for many inanimate neuter nouns, the accusative singular looks exactly the same as the nominative singular.

So:

• письмо = nominative singular
• письмо = accusative singular

You only know it is accusative from its role in the sentence.

Compare with a feminine noun:

• книга → книгу in the accusative

So Russian does mark the object, but sometimes the form happens to stay the same.

Because брать is the infinitive, meaning to take, while берёт is a conjugated form meaning takes / is taking.

Here, the subject is мой друг = he, so the verb must be in the 3rd person singular:

• я беру = I take
• ты берёшь = you take
• он/она берёт = he/she takes

So мой друг берёт means my friend takes / is taking.

The ё is important. It is pronounced yo, not just e.

So:

• берёт sounds roughly like biryot
• stress falls on -ёт

In many printed texts, Russian often writes е instead of ё, so you may sometimes see берет even though the correct pronunciation is still берёт.

That can be confusing for learners, so it is worth memorizing.

Both с and со mean from / off / with, depending on context. Here it means from/off.

Russian often uses со instead of с for ease of pronunciation, especially when the next word begins with certain consonant clusters or when с с... would sound awkward.

So:

• со стола sounds smoother than с стола

This is a very common pattern:

• со стола = from the table
• со стены = from the wall

Because after с/со meaning from/off, Russian uses the genitive case.

The base form is:

• стол = table

But after со in this meaning, it becomes:

• со стола = from the table / off the table

So:

• стол = nominative
• стола = genitive singular

This is one of the common uses of the genitive case: expressing source, origin, or movement from something.

It can mean either, depending on how natural the English translation is in context.

Literally, со стола means movement from the surface of the table. In English, that is often best translated as:

• off the table

But in many situations, English may also say:

• from the table

So the Russian phrase focuses on the idea that the letter is being taken away from the table.

Russian present tense often covers both:

• takes
• is taking

So Мой друг берёт письмо со стола could mean:

• My friend takes the letter from the table
• My friend is taking the letter off the table

The exact nuance depends on context. Russian does not always make the same simple present / present progressive distinction that English does.

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

This order is neutral and natural:

• Мой друг берёт письмо со стола.

But other orders are possible, for example:

• Письмо мой друг берёт со стола.
• Со стола мой друг берёт письмо.

These alternatives may change the emphasis or focus, but the core meaning stays similar because:

• друг is still the subject
• письмо is still the object
• со стола still shows where it is taken from

So in Russian, word order is often about information structure as much as grammar.

Yes. Many Russian nouns ending in -о are neuter, and письмо is one of them.

So:

• письмо = neuter singular noun

That is why you would say:

• моё письмо = my letter

This is useful because gender affects:

• adjectives
• pronouns
• past tense verbs
• some case endings

Of course, there are exceptions in Russian, but -о = often neuter is a very helpful pattern.

Берёт comes from брать, which is imperfective.

That matters because imperfective verbs often express:

• an action in progress
• a repeated or habitual action
• a general process, without emphasizing completion

So берёт письмо suggests the action of taking, without focusing on the final result.

The perfective partner is usually взять:

• Мой друг берёт письмо = my friend is taking / takes the letter
• Мой друг возьмёт письмо = my friend will take the letter
• Мой друг взял письмо = my friend took the letter

Aspect is one of the most important parts of Russian verbs, so even a simple sentence like this can be a good place to notice it.