Поставьте чашки на поднос, пожалуйста, а я пока поставлю тарелки.

Поставьте is the imperative form used for:

• you (plural), when speaking to more than one person
• formal/polite you, when speaking to one person respectfully

Поставь is the singular informal version, used with one person you address as ты.

So this sentence is either speaking politely to one person or addressing several people.

They are two forms of the same verb: поставить.

Here you have:

• Поставьте = imperative: put / place
• поставлю = first person singular future: I will put / I’ll place

So the sentence uses the same verb twice, but in different forms:

• one is a command to someone else
• the other is what the speaker says they will do

Поставить is a perfective verb, so its future form is a simple future: поставлю.

Russian often uses the perfective here because the focus is on completing the action: putting the plates down as a finished act.

Compare:

• поставлю = I’ll put them down, as a completed action
• буду ставить = I’ll be putting them down, focusing more on the process

In this context, поставлю sounds natural because the speaker means I’ll go ahead and place the plates.

Because на can take different cases depending on meaning.

Here there is movement onto the tray, so Russian uses:

• на + accusative → onto something

So:

• на поднос = onto the tray

If it meant on the tray as a location, with no movement, it would be:

• на подносе = on the tray

This is a very common Russian pattern:

• положить на стол = put onto the table
• лежать на столе = lie on the table

They are plural direct objects.

The nouns are:

• чашка → cups
• тарелка → plates

In this sentence they are in the accusative plural, because they are the things being placed.

For inanimate plural nouns, the accusative form is usually the same as the nominative form. So:

• nominative plural: чашки, тарелки
• accusative plural: чашки, тарелки

That is why the forms look unchanged.

Here пока means something like for now, in the meantime, or meanwhile.

So а я пока поставлю тарелки means: and I’ll put the plates down in the meantime / while that’s happening

This is not the goodbye meaning of пока.

Russian пока has several uses, including:

• bye / see you
• while
• for now / meanwhile

In this sentence, it clearly has the meanwhile sense.

А often marks a contrast, shift, or parallel action. It does not always mean a strong but.

Here а я пока поставлю тарелки means something like:

• and I, meanwhile, will put the plates down
• as for me, I’ll put the plates down for now
• while you do that, I’ll do the plates

So а helps divide the two actions:

• you put the cups on the tray
• I’ll put the plates down

Using и would sound more like simple addition. А is more natural for this kind of coordinated, contrasting division of tasks.

Yes, Russian could omit я, because the verb form поставлю already shows I.

But including я adds clarity or emphasis. It helps create a neat contrast:

• you put the cups on the tray
• I will put the plates down

So а я пока поставлю тарелки sounds slightly more explicit and balanced.

Yes. Пожалуйста softens the imperative and makes it polite.

Without пожалуйста, Поставьте чашки на поднос is still grammatically fine, but it sounds more direct.

With пожалуйста, it becomes a polite request:

• Please put the cups on the tray

Russian often uses the imperative with пожалуйста for polite requests.

It follows a very common pattern:

verb of motion/placement + object + destination

So here:

• Поставьте = put
• чашки = the cups
• на поднос = onto the tray

Literally, the structure is:

Put the cups onto the tray

This same pattern appears in many everyday sentences, for example:

• Положите книгу на стол = Put the book on the table
• Повесьте пальто на вешалку = Hang the coat on the hanger

Historically and semantically, yes, it is connected to the idea of setting something so that it stands, but in modern Russian поставить usually means to put / place / set down.

For learners, the safest translation here is simply:

• поставить = to put, to place

Russian often distinguishes between different verbs depending on how something is placed:

• поставить = set/stand something upright, or simply put it down in many contexts
• положить = lay something down
• повесить = hang something

In real usage, though, поставить чашки is completely normal and natural for put the cups down / place the cups.