La profesora no quiere castigar a nadie en clase.

La profesora means the teacher. In Spanish, you normally use the definite article with a noun when you are talking about a specific person or role.

• La profesora = the female teacher
• Una profesora = a female teacher

Using just Profesora by itself would usually happen only when directly addressing her, like Profesora, tengo una pregunta.

Also, profesora is the feminine form. The masculine form is profesor.

After querer (to want), Spanish uses an infinitive.

So the pattern is:

• querer + infinitive
• quiere castigar = she wants to punish

Examples:

• Quiero estudiar = I want to study
• Queremos salir = We want to go out

So castigar stays in the infinitive because it is the second verb.

In English, we say wants to punish. In Spanish, after querer, you do not use a separate word for to.

So:

• quiere castigar = literally wants punish, but naturally translated as wants to punish

This is very common in Spanish with one verb followed by another in the infinitive.

Yes, it is a kind of double negative, but that is completely normal in Spanish.

Spanish often uses:

• no + verb + nadie
• no + verb + nada
• no + verb + nunca

So:

• no quiere castigar a nadie = she doesn’t want to punish anyone

In English, we usually avoid double negatives in standard grammar, but in Spanish this structure is correct and expected.

Compare:

• No veo a nadie = I don’t see anyone
• No tengo nada = I don’t have anything

This is because of the personal a.

When the direct object is a person, or refers to people, Spanish usually adds a before it.

Since nadie refers to no person / nobody, you get:

• castigar a nadie

Compare:

• Veo a María = I see María
• No veo a nadie = I don’t see anyone
• Quiere ayudar a los alumnos = She wants to help the students

So the a is there because the person being punished is a human being, even if it is nobody / anyone.

No, that would be incorrect in standard Spanish.

If nadie comes after the verb, it normally needs no earlier in the sentence:

• La profesora no quiere castigar a nadie ✅

If nadie comes before the verb, then no is not used:

• Nadie quiere castigar a la profesora ✅ = Nobody wants to punish the teacher

So in your sentence, no is necessary.

In a negative sentence like this, nadie is usually best understood as anybody / anyone in natural English:

• No quiere castigar a nadie = She doesn’t want to punish anyone

But literally, nadie means nobody.

This is just a difference between how English and Spanish normally express negation.

En clase usually means in class or during class.

In this sentence, it most naturally means the teacher does not want to punish anyone in the classroom / during class time.

It can sometimes refer to:

• the physical place: in the classroom
• the situation or time: in class / during class

Spanish often leaves that slightly open, and the context tells you which sense is more important.

The normal, most natural order is:

• La profesora no quiere castigar a nadie en clase.

Spanish word order is somewhat flexible, but changes can sound marked or literary.

For example:

• En clase, la profesora no quiere castigar a nadie.
  This is also correct, and it emphasizes in class.

But the original order is the most neutral and standard.

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

• quiere can mean he/she/you formal wants

Since la profesora is already there, adding ella would be unnecessary:

• La profesora no quiere castigar a nadie ✅
• Ella no quiere castigar a nadie ✅, but only if the context already makes clear who she is
• La profesora ella no quiere... ❌ in normal usage

Spanish normally avoids repeating the subject unless there is a reason to emphasize it.

Not normally in everyday Spanish.

Castigar is the common verb for to punish.
Punir exists, but it is much less common and sounds more formal or literary in most contexts.

So for ordinary conversation and general use, castigar is the right choice.

In this sentence, profesora specifically tells you the teacher is female.

• la profesora = the female teacher
• el profesor = the male teacher

Spanish nouns for professions often change form depending on gender. Since the sentence says la profesora, the speaker is clearly referring to a woman.