No dobles la rama, que puede romperse.

Because this is a negative command addressed to tú.

In Spanish, negative commands for tú use the present subjunctive, not the normal present tense:

• doblas = you bend / you are bending
• no dobles = don’t bend

So:

• Dobla la rama. = Bend the branch.
• No dobles la rama. = Don’t bend the branch.

The ending -es here is the tú form of the present subjunctive of doblar.

Compare:

• yo: doble
• tú: dobles
• usted: doble
• nosotros: doblemos
• vosotros: dobléis
• ustedes: doblen

So no dobles means the speaker is telling one person informally: don’t bend it.

Here doblar means to bend.

It can also mean other things depending on context, such as:

• to turn: doblar a la derecha = to turn right
• to fold: doblar la ropa = to fold clothes

In No dobles la rama, the meaning is clearly don’t bend the branch.

Because rama is a feminine noun in Spanish:

• la rama = the branch

Even though it ends in -a, that is normal for many feminine nouns. So the article must be la, not el.

Here que means something like because / since / as, introducing the reason or warning:

• No dobles la rama, que puede romperse.
• Don’t bend the branch, because it could break.

In everyday Spanish, que is often used this way after a warning or command. It sounds natural and conversational.

Yes, you could say:

• No dobles la rama, porque puede romperse.

That also means Don’t bend the branch, because it could break.

The version with que is very common and natural in spoken Spanish. It can sound slightly more immediate or conversational after an instruction or warning.

Because this clause is stating a real possibility, not expressing doubt or desire in a way that requires the subjunctive.

• puede = present indicative of poder
• pueda = present subjunctive

In que puede romperse, the speaker means it can/might break, which is treated as a normal factual possibility, so indicative is used.

Romper means to break.
Romperse means to break / to get broken in an intransitive or reflexive-style sense.

So:

• romper algo = to break something
• romperse = to break, to snap, to get broken

In this sentence, the branch itself is the thing that may break:

• La rama puede romperse. = The branch can break.

The se helps express that the branch undergoes the action itself, rather than someone actively breaking it.

Not in the literal sense of doing something to itself.

This is one of those common Spanish uses of se where English often just uses an ordinary intransitive verb:

• El vaso se rompió. = The glass broke.
• La puerta se abrió. = The door opened.
• La rama puede romperse. = The branch could break.

So it is often called pronominal or medio/passive-like usage, rather than truly reflexive in meaning.

With a conjugated verb plus an infinitive, object or reflexive pronouns can often go in two places:

• before the conjugated verb
• attached to the infinitive

So both are possible:

• puede romperse
• se puede romper

In this sentence, puede romperse is completely natural.
Both versions mean essentially the same thing here.

It can suggest either can break or might break, depending on context.

In a warning like this, English often prefers:

• it might break
• it could break

Spanish puede often covers that idea of possibility without needing a separate word like might.

The comma separates the warning from the explanation:

• No dobles la rama, = Don’t bend the branch,
• que puede romperse. = because it might break.

It helps show that the second part gives the reason for the first part.

Yes, it sounds natural.

A speaker in Spain could definitely say:

• No dobles la rama, que puede romperse.

It sounds like a normal warning in everyday speech. Depending on tone or context, they might also say:

• No dobles la rama, que se rompe.
• No dobles la rama, porque puede romperse.
• No la dobles, que puede romperse.

All are natural, though the exact nuance changes a little.

Yes. Since la rama is a direct object, you can replace it with la:

• No la dobles, que puede romperse.

That means Don’t bend it, it might break.

This is very common once the object is already understood from context.

Because dobla is the affirmative tú command or the él/ella/usted present form, but negative tú commands work differently.

Compare:

• Dobla la rama. = Bend the branch.
• No dobles la rama. = Don’t bend the branch.

So for tú:

• affirmative command: dobla
• negative command: no dobles

For usted:

• No doble la rama, que puede romperse.

For vosotros in Spain:

• No dobléis la rama, que puede romperse.

So the sentence changes depending on who you are addressing:

• tú: no dobles
• usted: no doble
• vosotros: no dobléis
• ustedes: no doblen

Yes. It is a very useful pattern:

• No + subjunctive command + noun/pronoun, que + indicative

For example:

• No corras, que te vas a caer. = Don’t run, you’re going to fall.
• No lo toques, que quema. = Don’t touch it, it burns / it’s hot.
• No dobles la rama, que puede romperse. = Don’t bend the branch, it might break.

This is a common and natural way to give warnings in Spanish.