Не путай дату встречи с датой экзамена.

Не путай is a negative imperative: it means don’t confuse / don’t mix up.

• путай = the imperative form of путать
• не = makes it negative

This form is used when speaking to one person in an informal way.

So the sentence is addressed to one person, like a friend, child, classmate, or someone you speak to with ты.

Because путай is a command, while путаешь is a normal present-tense form.

• ты путаешь = you confuse / you are confusing
• не путай = don’t confuse

English often uses the bare verb for commands, and Russian does something similar with a special imperative form.

Yes. Не путай is singular informal.

If you are speaking:

• formally to one person, or
• to several people,

you would say:

Не путайте дату встречи с датой экзамена.

So:

• не путай = informal singular
• не путайте = formal singular or plural

дату is the accusative singular of дата.

It appears because дата встречи is the direct object of the verb путать. In other words, it is the thing you are being told not to confuse.

Basic pattern:

путать что?
дату

For feminine nouns ending in -а, the accusative singular usually changes to -у:

• дата → дату
• книга → книгу

Because the verb pattern is:

путать X с Y = to confuse X with Y

After с in this construction, Russian uses the instrumental case.

So:

• дата → датой in the instrumental singular
• therefore: с датой экзамена

This is a very useful pattern to remember as a whole:

путать что-то с чем-то

They are in the genitive case because Russian often expresses of relationships with a noun in the genitive.

So:

• дата встречи = the date of the meeting
• дата экзамена = the date of the exam

This is a very common structure:

• план урока = plan of the lesson
• начало фильма = beginning of the film
• номер телефона = phone number

So here:

• встречи = genitive singular of встреча
• экзамена = genitive singular of экзамен

Because the same noun has to change depending on its role in the sentence.

• дату = accusative, because it is the direct object
• датой = instrumental, because it comes after с in путать X с Y

Russian nouns change form much more than English nouns do, so seeing the same word appear in different cases in one sentence is completely normal.

Yes, and this is an important nuance.

Не путай uses the imperfective verb путать. In negative commands, the imperfective often sounds like:

• a general instruction
• a warning against doing something
• don’t be mixing these up

A perfective version such as Не перепутай дату встречи с датой экзамена is also possible. That sounds more like:

• make sure you don’t mix them up
• a warning about a specific future mistake

So both can work, but the nuance is different:

• Не путай = general or immediate don’t confuse them
• Не перепутай = be careful not to mix them up

You might hear that, and people would probably understand it, but путать X с Y is the more standard and clearer pattern.

So:

• more natural: Не путай дату встречи с датой экзамена
• less standard / less explicit: Не путай дату встречи и дату экзамена

Using с makes the relationship very clear: don’t confuse one thing with the other.

Because Russian has no articles.

Russian does not have direct equivalents of a and the. Whether something is definite or indefinite is usually understood from:

• context
• word order
• common sense
• intonation

So дата встречи can mean the date of the meeting or sometimes a meeting date, depending on context.

Yes. Russian word order is more flexible than English word order because the cases already show the grammatical relationships.

The given sentence is neutral and natural:

Не путай дату встречи с датой экзамена.

But you could also say:

Не путай дату экзамена с датой встречи.

That would still mean the same basic thing, but the emphasis shifts slightly depending on which date you mention first.

So the standard meaning stays clear because:

• дату is accusative
• с датой is instrumental

A helpful stress pattern is:

Не путАй дАту встрЕчи с дАтой экзамЕна.

A few notes:

• не is usually unstressed
• путай has stress on the second syllable
• дата has stress on the first syllable
• встреча / встречи has stress on е
• экзамен / экзамена has stress on е

If you want to sound natural, try saying it smoothly as one warning rather than pausing after every word.