Мы избрали президента.

Because президента is the accusative singular form, and here it is the direct object of the verb.

For masculine animate nouns in Russian, the accusative singular usually looks like the genitive singular:

• nominative: президент
• genitive: президента
• accusative: президента

Since a president is a person, Russian treats the noun as animate, so you get президента.

Избрали is the past tense plural form of the verb избрать.

So the breakdown is:

• infinitive: избрать
• past plural: избрали

It means the action happened in the past, and the subject is plural: we.

In Russian past tense, plural subjects take the ending -ли.

Compare:

• я избрал / избрала — I elected
• ты избрал / избрала — you elected
• он избрал — he elected
• она избрала — she elected
• мы избрали — we elected
• они избрали — they elected

So -ли tells you the subject is plural.

Not by itself.

This is important: in the past tense, Russian verbs show gender in the singular and number in the plural, but they do not show person.

So избрали could mean:

• we elected
• you all elected
• they elected

That is why мы is useful here: it makes the subject clear.

Both can involve choosing, but избрать is often more formal and is especially common for electing someone to a position.

So:

• избрать президента = to elect a president
• выбрать = to choose/select in a more general sense

In this sentence, избрать is the natural verb because it is about electing a president.

Избрать is perfective.

That means it presents the action as completed: the election happened and was brought to a result.

So Мы избрали президента has the sense of We elected the president as a completed event.

The imperfective partner is избирать. That would be used for things like:

• process
• repetition
• general fact
• ongoing action

For example, избирали президента could suggest the process of electing, or repeated elections in some context.

Russian often omits subject pronouns, but here мы is quite helpful because the past tense form избрали does not tell you whether the subject is we, you plural, or they.

So:

• Мы избрали президента = clearly we elected the president
• Избрали президента = subject depends on context

Unlike present-tense forms, the past tense does not identify person clearly enough on its own.

Yes, but not in the same rigid way as in English.

The neutral order is:

• Мы избрали президента.

This simply states the fact.

But Russian can move words around for emphasis:

• Президента мы избрали.
  Emphasizes the president
• Мы президента избрали.
  Can sound contrastive or emphatic depending on context

The basic meaning stays the same because the cases show the grammatical roles.

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

That means президента could, depending on context, mean:

• the president
• a president

You understand which one is meant from the situation, context, or general knowledge. In many contexts, Мы избрали президента will naturally be understood as We elected the president, but Russian itself does not mark that with an article.

The stress is:

• Мы избра́ли президе́нта

So the stressed syllables are:

• избра́ли
• президе́нта

A rough pronunciation guide:

• Мы ≈ my but with a Russian ы sound
• избра́ли ≈ eez-BRA-lee
• президе́нта ≈ pree-zee-DYEN-ta

The stress matters a lot in Russian, so it is worth learning the stressed syllables together with the word.

In many contexts, избрать can mean choose in a formal or elevated sense, but with президента, the natural meaning is elect.

So although the verb has a broader historical or stylistic range, in this sentence learners should understand it as the standard expression for electing a president.