No recalientes el café otra vez; ya sabe demasiado amargo.

Because this is a negative tú command.

In Spanish, negative commands for tú use the present subjunctive:

• recalentar → recalientes
• so No recalientes = Don’t reheat

Compare:

• Recalienta el café = Reheat the coffee
• No recalientes el café = Don’t reheat the coffee

This is a very common pattern:

• No hables
• No comas
• No salgas

Yes.

• calentar = to heat, warm up
• recalentar = to reheat, heat again

The prefix re- adds the idea of again.

So:

• Calienta el café = Heat the coffee
• Recalienta el café = Reheat the coffee

In this sentence, recalentar is used because the coffee has apparently already been heated before.

Because Spanish often leaves out subject pronouns when they are clear from the verb ending.

In No recalientes, the ending -es already shows that the speaker is talking to tú.

So both are possible:

• No recalientes el café otra vez
• Tú no recalientes el café otra vez

The version without tú is more neutral and more natural in most everyday situations. Adding tú usually gives extra emphasis, contrast, or emotion.

Spanish uses articles more often than English does.

Here, el café refers to a specific coffee already known in the situation, not coffee in general.

So Spanish naturally says:

• No recalientes el café

rather than leaving the article out.

English often says coffee with no article, but Spanish commonly uses el / la / los / las when talking about a specific thing in front of you or already understood from context.

Otra vez means again or one more time.

Yes, you could also say de nuevo:

• No recalientes el café otra vez
• No recalientes el café de nuevo

Both are correct. In everyday speech, otra vez is very common and sounds natural.

Here it means again, not another time in the future.

Ya here means something like already, by now, or as it is already.

It gives the idea that the coffee has already reached that point:

• ya sabe demasiado amargo = it already tastes too bitter

So ya helps explain why the speaker says not to reheat it again.

It often adds a sense of:

• this is already the case
• at this point
• now that things stand this way

Saber has two different meanings:

1. to know
2. to taste

With food and drink, saber often means to taste.

So here:

• el café sabe amargo = the coffee tastes bitter

The form sabe is third person singular, matching el café.

That is why sabe here does not mean he/she knows. The context makes it clear that it means tastes.

Because Spanish uses two different patterns:

• saber + adjective = to taste + quality

  • sabe amargo
  • sabe dulce
  • sabe raro

• saber a + noun = to taste like + thing

  • sabe a limón
  • sabe a humo
  • sabe a café

In this sentence, amargo is an adjective describing the taste, so a is not used.

So:

• sabe amargo = it tastes bitter
• sabe a limón = it tastes like lemon

Because demasiado works like too here, and it goes before the adjective:

• demasiado amargo = too bitter

Compare:

• muy amargo = very bitter
• demasiado amargo = too bitter

So demasiado does not just describe intensity; it suggests excess.

Yes, you could.

There is a slight difference in focus:

• sabe demasiado amargo focuses on how it tastes
• está demasiado amargo focuses more on its current state

In everyday speech, both can sound natural depending on what you want to emphasize. With food and drink, Spanish often uses saber when talking directly about flavor.

So the given sentence is highlighting the coffee’s taste.

The semicolon links two closely connected ideas:

• No recalientes el café otra vez
• ya sabe demasiado amargo

It works a bit like a stronger comma and avoids repeating the relationship with a word like because.

A more explicit version would be:

• No recalientes el café otra vez, porque ya sabe demasiado amargo

So the semicolon is mainly a punctuation choice that connects the warning with the reason.