Debes obedecer a tu madre cuando te dice que cruces con cuidado.

In Spanish, subject pronouns are often left out because the verb ending already shows who the subject is.

• debes = you must / you should
• The -es ending tells us the subject is tú

So Debes obedecer... is completely natural.
You could say Tú debes obedecer..., but that would usually add emphasis, as if contrasting you with someone else.

This is because tu madre is a person, and Spanish often uses the personal a before a human direct object.

So:

• obedecer a tu madre = to obey your mother
• ver a tu madre = to see your mother
• escuchar a tu madre = to listen to your mother

Even though English does not use a preposition here, Spanish normally does when the object is a specific person.

No, they are related but not the same.

• obedecer = to obey
• escuchar = to listen to

So:

• Debes obedecer a tu madre = You should do what your mother tells you.
• Debes escuchar a tu madre = You should listen to what your mother says.

Listening does not always mean obeying, but obeying usually implies following instructions.

Te means to you.

• dice = she says / tells
• te dice = she tells you

Here, tu madre is the person speaking, and te is the person receiving the instruction.

So:

• tu madre te dice = your mother tells you

Because the sentence is referring to something presented as a real or habitual situation:

• cuando te dice... = when she tells you... / whenever she tells you...

This is why the indicative is used: dice.

If the sentence were talking about a future or hypothetical situation, Spanish often uses the subjunctive after cuando:

• cuando te diga... = when she tells you... (in the future, on some later occasion)

So in your sentence, dice suggests a general or repeated situation, not a one-time future event.

Because after decir meaning to tell someone to do something, Spanish uses the subjunctive.

So:

• te dice que cruces con cuidado = she tells you to cross carefully

This is not just reporting information; it is expressing an instruction or command. That is why cruces is used.

Compare:

• Te dice que cruzas mal = She tells you that you cross badly.
  
  • Here she is giving information/opinion about how you cross.
• Te dice que cruces con cuidado = She tells you to cross carefully.
  
  • Here she is giving an instruction.

Cruces is the present subjunctive form of cruzar for tú.

From cruzar:

• yo cruce
• tú cruces
• él/ella cruce
• nosotros crucemos
• vosotros crucéis
• ellos crucen

In this sentence:

• que cruces = that you cross

But in natural English, it is usually translated as to cross after tell someone:

• te dice que cruces = she tells you to cross

It can feel like when or whenever, depending on context.

In this sentence, it most naturally suggests a general repeated situation:

• cuando te dice... = when / whenever she tells you...

Because the rest of the sentence is a general statement about what you should do, English might naturally understand it as whenever your mother tells you...

Both are possible in Spanish, but con cuidado is much more common and natural in everyday speech.

• cruzar con cuidado = to cross carefully
• cruzar cuidadosamente = also possible, but more formal or less conversational

Spanish often prefers a prepositional phrase like con cuidado where English uses an adverb ending in -ly.

Other examples:

• hablar con calma = speak calmly
• hacer algo con paciencia = do something patiently

Because Spanish normally uses a possessive adjective directly before the noun:

• tu madre = your mother
• mi padre = my father
• su casa = his/her/their house

You do not usually say la tu madre in standard Spanish.

They are very close, but not always identical in tone.

• debes = you should / you must
• tienes que = you have to

In many contexts, both can mean obligation:

• Debes obedecer a tu madre
• Tienes que obedecer a tu madre

However, deber can sometimes sound slightly more like moral advice or duty, while tener que often sounds like practical necessity. In real life, the difference is not always strong.

Yes.

• tu madre = your mother
• tu mamá = your mum / your mom

Madre is perfectly correct, but mamá often sounds warmer and more natural in everyday family speech.
The choice depends on tone and style.

So you could also hear:

• Debes obedecer a tu mamá cuando te dice que cruces con cuidado.

Because deber is a modal-type verb that is followed by an infinitive.

• debes obedecer = you must obey
• debes estudiar = you must study
• debes esperar = you must wait

This works similarly to English must or should, which are also followed by a base verb.

Not in this sentence.

After decirle a alguien to mean tell someone to do something, Spanish normally uses:

• decirle a alguien que + subjunctive

So:

• te dice que cruces con cuidado = correct

Para que usually expresses purpose, not reported instructions in this structure:

• Te lo repite para que cruces con cuidado = She repeats it so that you cross carefully.

So para que would change the meaning.

With debes, it expresses obligation or strong advice.

Depending on context, debes can sound like:

• you should
• you ought to
• you must

So the sentence is not directly commanding Obedece...; instead, it states that obeying your mother is what you are expected to do.