Возьми пластырь из аптечки на всякий случай.

Возьми is the imperative of the perfective verb взять. It suggests a single, completed action: take one now / make sure you take it.

A learner will often compare it with бери, the imperative of брать, which is imperfective. Бери can sound more like:

• go ahead and take it
• take it regularly / repeatedly
• start taking it

In this sentence, the speaker means one specific action, so возьми is the natural choice.

It is:

• imperative
• singular
• informal
• from the verb взять = to take

So it is used when speaking to one person in an informal way.

If you wanted the formal or plural version, you would say:

• Возьмите пластырь из аптечки на всякий случай.

Пластырь is the direct object of возьми, so it is in the accusative case.

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

So:

• nominative: пластырь
• accusative: пластырь

That is why the word does not visibly change here.

Пластырь can refer to a plaster, adhesive bandage, or sometimes medical tape, depending on context.

In this sentence, since it comes from a first-aid kit, it most naturally means something like:

• a bandage
• a plaster
• an adhesive bandage

Russian can also use лейкопластырь for adhesive plaster / band-aid-type plaster, which is a bit more specific.

The preposition из means out of / from, and it requires the genitive case.

So:

• nominative: аптечка
• genitive: аптечки

That is why the sentence says из аптечки = from the first-aid kit.

No. This is an important vocabulary distinction:

• аптека = pharmacy / drugstore
• аптечка = first-aid kit / medicine box

So из аптечки does not mean from the pharmacy. It means from the first-aid kit.

На всякий случай is a very common fixed expression meaning:

• just in case
• for safety
• to be safe

Literally, it is something like for any case / for any eventuality, but in normal English you usually translate it as just in case.

It is best learned as a whole phrase.

This expression uses на with the accusative case.

Here:

• всякий agrees with случай
• случай is masculine inanimate
• in the accusative singular, masculine inanimate nouns often look the same as the nominative

So the phrase appears as:

• на всякий случай

Because it is a fixed idiomatic expression, learners usually memorize it as one chunk rather than building it from scratch every time.

Good question. Russian often leaves с собой unstated if the meaning is obvious from context.

So:

• Возьми пластырь из аптечки на всякий случай.

already naturally suggests take a bandage along / make sure you have one.

If you want to make that idea more explicit, you can say:

• Возьми с собой пластырь из аптечки на всякий случай.

That would mean Take a bandage from the first-aid kit with you, just in case.

Yes. Russian word order is fairly flexible, and changing it usually changes emphasis, not the basic meaning.

For example:

• На всякий случай возьми пластырь из аптечки.
• Возьми из аптечки пластырь на всякий случай.

These still mean basically the same thing, but the focus shifts slightly:

• putting на всякий случай first emphasizes the precaution
• putting из аптечки earlier emphasizes where to get it from

The original order is very natural and neutral.

Russian has no articles, so it does not directly mark the difference between a bandage and the bandage the way English does.

Russian relies on:

• context
• word order
• intonation
• sometimes words like этот = this

So пластырь here could be understood as a bandage or the bandage, depending on the situation. In this sentence, English would most naturally say a bandage / a plaster.