Learn Hardcore Russian: Мой друг часто присылает мне сообщения вечером. - My friend often sends me messages in the evening.

Кто? Что? (Who? What?) → мой друг (my friend) → nominative.
Присылает кого? что? (sends whom? what?) → сообщения (messages) → direct object (accusative).

Моего друга would be in the genitive (or accusative masculine animate), which you’d use, for example, after certain prepositions or verbs, or as an object, not as the subject:

Я жду моего друга. – I am waiting for my friend. (Here, моего друга is the object.)

In this sentence, мой друг is clearly the subject, so nominative is required.

What case is мне, and why is it used instead of меня?

Мне is the dative case of я (I → to me).

Russian uses the dative for the indirect object – the person to whom something is given, sent, shown, etc.

Verb: присылать – to send (to someone)
Direct object (what is sent): сообщения – messages (accusative)
Indirect object (to whom): мне – to me (dative)

So the structure is:
Кто? Мой друг → subject (nominative)
Что делает? присылает → verb
Кому? мне → indirect object (dative)
Что? сообщения → direct object (accusative)

Меня is accusative/genitive and would be wrong here; it would mean “sends me” (as in sending me somewhere), not “sends messages to me”.

Why is there no preposition like “to” in присылает мне (to me)?

In Russian, the idea of “to someone” is usually expressed by the dative case alone, without a preposition.

English: sends messages to me
Russian: присылает мне сообщения

The dative ending (here the form мне) already contains the “to” meaning.
Using a preposition like к мне with присылать here would sound unnatural or change the meaning.

What is the difference between присылать, посылать, and отправлять?

All three can be translated as to send, but there are nuances:

присылать / прислать
- Focuses on sending so that it reaches the speaker or some destination.
- Often used for things like emails, letters, parcels that arrive to you.
- Prefix при- suggests arrival.
посылать / послать
- More general “to send,” often for sending someone/something away.
- Can sound a bit more bookish or, in some contexts, old-fashioned for modern electronic communication.
отправлять / отправить
- Very common neutral verb for sending (mail, messages, packages).
- Often used in tech contexts: отправить сообщение – to send a message.

In Мой друг часто присылает мне сообщения вечером, using присылает emphasizes that the messages are sent to me and reach me (e.g., I regularly receive them).

Why is присылает used here and not прислал?

Присылает is present tense, imperfective aspect:

присылать (imperfective) – to send (repeatedly, in general, as a process)
прислать (perfective) – to send (one completed act or the result)

The sentence describes a habitual, repeated action (“My friend often sends me messages in the evening”), so Russian uses the imperfective:

Мой друг часто присылает мне сообщения вечером.
Habitual action → imperfective present.

If you used прислал, it would be past tense, perfective:

Мой друг вчера прислал мне сообщение. – My friend sent me a message yesterday. (one completed event)

Where can часто go in the sentence? Is the word order fixed?

The basic, neutral word order is:

Мой друг часто присылает мне сообщения вечером.

This puts часто right before the verb, which is very typical for adverbs of frequency.

However, Russian word order is more flexible than English. You can move часто to change emphasis:

Часто мой друг присылает мне сообщения вечером.
Emphasis on how often it happens (“Often, my friend sends me messages in the evening”).
Мой друг присылает мне часто сообщения вечером.
Possible, but less natural; can sound a bit clumsy or give extra emphasis on часто.

The original version is the most natural, neutral choice. For learners, placing adverbs like часто, редко, обычно just before the verb is a good default.

Why is it сообщения and not сообщение?

Сообщения is the plural form (nominative or accusative plural) of сообщение (message).

The English sentence says messages (plural), and Russian matches that:

одно сообщение – one message
два / три / много сообщений – two / three / many messages (genitive plural)
присылает сообщения – sends messages (accusative plural, same form as nominative plural for neuter inanimate nouns)

You could say сообщение if you meant specifically “a message”:

Мой друг часто присылает мне сообщение вечером.
This would sound more like “My friend often sends me a message in the evening” (usually one).

But in most contexts, if you mean multiple or unspecific messages, сообщения is more natural.

What case is сообщения here? It looks like both nominative plural and genitive singular.

You’re right: сообщения can be:

Nominative plural: эти сообщения интересные – these messages are interesting.
Genitive singular: нет сообщения – there is no message.

In this sentence, сообщения is the direct object of присылает, and the noun is inanimate and neuter. For such nouns, the accusative plural is identical to the nominative plural.

So here it is accusative plural:

Кого? Что? (whom? what?) → сообщения (messages, accusative plural)

Why is вечером used without a preposition, instead of something like в вечер?

Вечером is the instrumental case of вечер (evening), and it functions as an adverbial expression of time meaning:

вечером = “in the evening”, “during the evening”

Russian often uses the instrumental (or sometimes genitive) without a preposition to answer “when?”:

утром – in the morning
днём – in the daytime
вечером – in the evening
ночью – at night

You would not say в вечер in this meaning; that sounds wrong for time. The correct idiomatic form is simply вечером.

If you want to express repeated evenings in general, you can also use по вечерам – “in the evenings” (habitually):

Мой друг по вечерам часто присылает мне сообщения.

Can мне move to another position, like Мой друг мне часто присылает сообщения вечером?

Yes, мне can move, and Russian allows different word orders:

Мой друг часто присылает мне сообщения вечером.
Neutral, very natural.
Мой друг мне часто присылает сообщения вечером.
Also grammatically correct. Slightly more focus on мне (to me), as if contrasting with others.
Мой друг часто присылает сообщения мне вечером.
Possible, but puts extra emphasis on мне, often used when contrasting:
- Ему не пишет, а мне часто присылает сообщения вечером.
  He doesn’t write to him, but often sends messages to me in the evening.

The original sentence is the most typical neutral option.

Why is it мой друг, not моя друг or моё друг?

The noun друг (friend) is masculine in Russian.

The possessive мой / моя / моё / мои agrees in gender and number with the noun it modifies:

мой – masculine singular
моя – feminine singular
моё – neuter singular
мои – plural

Since друг is masculine singular:

мой друг – my (male) friend

If you were talking about a female friend, you’d typically use подруга (a different word, feminine):

моя подруга – my (female) friend

Could you drop мой and just say Друг часто присылает мне сообщения вечером?

You can say Друг часто присылает мне сообщения вечером, but it changes the nuance.

Мой друг... – clearly “my friend”; you’re introducing or talking about your friend.
Друг... without a possessive can sound:
- more generic (“a friend” in general),
- or rely on context (if it’s already clear whose friend is being discussed).

In ordinary conversation, if you mean specifically my friend, you almost always say мой друг.