Я помыла черешню и положила её в пакет, чтобы взять с собой на дачу.

Because Russian past-tense verbs show gender in the singular.

• помыла, положила = feminine singular
• помыл, положил = masculine singular
• помыло, положило = neuter singular
• помыли, положили = plural

So this sentence tells us the speaker is female. A male speaker would say:

Я помыл черешню и положил её в пакет...

Russian uses the perfective aspect when talking about actions as completed results.

Here the speaker:

• washed the cherries completely
• put them into the bag
• wants to take them along as one completed action

That is why Russian uses:

• помыть instead of мыть
• положить instead of класть
• взять instead of брать

If you used imperfective forms, the focus would be more on process, repetition, or an unfinished action.

Because черешню is the accusative case, used for the direct object of the verb.

The base form is черешня. For many feminine nouns ending in -я, the accusative singular changes to -ю:

• черешня → черешню
• неделя → неделю
• семья → семью

Since the speaker washed the cherries, черешня is the object, so it becomes черешню.

In Russian, names of fruit are often used as a mass noun in the singular when talking about them in a general, collective way.

So:

• помыть черешню = to wash some cherries / the cherries

Russian is not focusing on each individual cherry here, but on the fruit as a quantity.

You can also hear plural forms like черешни, especially if the speaker is thinking of individual cherries, quantities, or varieties. But помыть черешню is very natural.

These are two different kinds of cherries.

• черешня = sweet cherry
• вишня = sour cherry / tart cherry

This distinction is much clearer in Russian than in everyday English, where both may simply be called cherries.

So the sentence specifically refers to sweet cherries.

её means it or her, and here it refers back to черешню.

So:

• положила её в пакет = put it into the bag

Russian often uses a pronoun like this to make the sentence smoother and clearer after the first verb.

Yes, it could be omitted if the meaning is obvious:

• Я помыла черешню и положила в пакет...

That is still understandable. But её helps connect the second action clearly to черешню, so it sounds natural.

Because Russian uses different cases depending on whether you mean:

• movement into something
• location inside something

Here it is movement into the bag, so Russian uses:

• в + accusative → в пакет

Compare:

• положила в пакет = put into the bag
• лежит в пакете = is lying in the bag

So:

• в пакет = destination
• в пакете = location

Also, пакет here usually means a bag, often a shopping bag or plastic bag, not necessarily a formal package.

Чтобы introduces a purpose clause. In English, it often means:

• so that
• in order to

So:

• ..., чтобы взять с собой на дачу = ..., in order to take with me to the dacha

When the subject is the same as in the main clause, Russian often uses:

• чтобы + infinitive

That is exactly what happens here.

Because the speaker means one specific completed action: taking the cherries along.

After чтобы, Russian often uses the perfective infinitive when talking about a concrete goal or result:

• чтобы взять = in order to take
• чтобы купить = in order to buy
• чтобы открыть = in order to open

Using брать would sound less natural here because it suggests a more ongoing, repeated, or process-like action, not one single intended result.

С собой literally means with oneself, but in natural English it often means:

• with me
• along
• on me
  depending on context

In this sentence:

• взять с собой = take along / take with me

Even though the speaker is I, Russian still uses the fixed expression с собой, not с мной.

Some common examples:

• Я взял книгу с собой. = I took the book with me.
• У меня с собой нет денег. = I don’t have money on me.

So взять с собой is a very common chunk worth remembering as a whole.

Because Russian normally says на дачу when talking about going to someone’s dacha or country house.

This is just the usual Russian pattern:

• на дачу = to the dacha
• на даче = at the dacha
• с дачи = from the dacha

Even though дача is a building, Russian treats it idiomatically with на, not в, when talking about going there as a destination.

If you specifically wanted to say into the house/building, you would more likely say something like:

• в дом
• в дачный домик

But for the normal idea of going there for the weekend or summer, на дачу is the standard expression.

Yes. Russian often omits subject pronouns when the subject is clear from context.

So this could also be:

• Помыла черешню и положила её в пакет, чтобы взять с собой на дачу.

That sounds natural if it is already clear who is speaking.

Including Я is also fine. It can make the sentence feel a bit more explicit, contrastive, or simply more self-contained.

No, Russian word order is flexible, though not random.

The given order is a neutral, natural way to say it:

• Я помыла черешню и положила её в пакет, чтобы взять с собой на дачу.

But Russian can move parts around for emphasis. For example:

• Черешню я помыла и положила её в пакет...
  This puts extra focus on черешню.

• Я положила её в пакет, чтобы взять с собой на дачу.
  This focuses more on the act of putting it into the bag.

So the original sentence is not the only possible order, but it is a very normal default one.