Pon la taza sobre el posavasos y remueve el café con la cucharilla pequeña.

Pon is the affirmative informal command of poner for tú.

So:

• poner = to put
• pon = put

This sentence is giving an instruction to one person in an informal way, so pon is the correct form.

A few useful comparisons:

• Pon la taza... = Put the cup... (tú, informal)
• Ponga la taza... = Put the cup... (usted, formal)
• Poned la taza... = Put the cup... (informal plural in Spain)
• Pongan la taza... = Put the cup... (formal plural, or general plural in Latin America)

Also, pon is irregular, so it does not follow the most basic command pattern.

Spanish often leaves subject pronouns out because the verb form already shows who the subject is.

Here, pon and remueve already tell you that the speaker is addressing tú. So adding tú is usually unnecessary.

You could say Tú pon la taza..., but that would normally add emphasis, contrast, or impatience.

In Spanish, definite articles are used very often, including in instructions, when the objects are understood in the situation.

So la taza does not necessarily mean a very specific cup already mentioned earlier in the conversation. It can simply mean the cup involved here, which sounds natural in Spanish.

Compare:

• Pon la taza sobre el posavasos = natural instruction
• Pon una taza sobre un posavasos = put a cup on a coaster, any cup/coaster

Spanish generally uses articles more often than English does.

Here sobre means on or on top of.

So sobre el posavasos means the cup should be placed on the coaster.

Other options:

• encima del posavasos = on top of the coaster
• en el posavasos = less natural here, because en often means in or a more general on/at, but with a flat object like a coaster, sobre or encima de is clearer

In this sentence, sobre is a very natural choice.

Posavasos is one of those Spanish nouns that end in -s even in the singular.

So:

• el posavasos = the coaster
• los posavasos = the coasters

The form stays the same; only the article changes.

It is a compound noun:

• posa- = rest/holder
• vasos = glasses

So literally it is something like glass-rest, but the actual meaning is coaster.

Yes. In this sentence, remueve means stir.

This is a good example of a false friend. English remove usually means take away, but Spanish remover can mean stir, especially in Spain.

So:

• remover el café = to stir the coffee

If you want remove/take away in Spanish, you would more often use verbs like:

• quitar
• retirar
• sacar
  depending on the context.

Also, in some other Spanish-speaking regions, revolver is more common for stir.

Con means with, and here it introduces the instrument used to do the action.

So:

• remueve el café con la cucharilla pequeña = stir the coffee with the small spoon

This is the normal way to say what tool or utensil you use to perform an action.

Cucharilla means small spoon. In Spain, it is a very common word for a spoon used for coffee, tea, dessert, or similar things.

Compare:

• cuchara = spoon, often a more general or larger spoon
• cucharilla = small spoon

The ending -illa is a diminutive ending, so it often suggests small size.

In other varieties of Spanish, you may also hear cucharita for small spoon.

In Spanish, descriptive adjectives usually come after the noun.

So:

• la cucharilla pequeña = the small spoon

That is the normal, neutral order.

If you put the adjective before the noun, it often sounds more literary, emotional, or emphatic:

• la pequeña cucharilla

That is possible, but it does not sound as neutral as la cucharilla pequeña in an everyday instruction.

The accent mark shows where the stress goes: ca-FÉ.

Without the accent, the word would not follow normal Spanish spelling expectations for pronunciation. The written accent tells you that the final syllable is stressed.

So:

• café = coffee

It is also a useful reminder that many Spanish words borrowed into English keep their accent in Spanish, even if English often drops it.

The given word order is the most natural neutral order for a simple instruction:

• Pon la taza sobre el posavasos y remueve el café con la cucharilla pequeña.

But Spanish word order is somewhat flexible. For example, you could say:

• Con la cucharilla pequeña, remueve el café.

That puts extra focus on the spoon.

Still, for everyday instructions, the original order sounds the most straightforward and natural.