La profesora señaló dos errores en mi texto.

Because profesora is the feminine form of profesor. Spanish nouns for people often change ending to match gender:

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

The article also changes to match:

• el with masculine singular nouns
• la with feminine singular nouns

So la profesora means the teacher is female.

Señaló is the preterite tense, third person singular, from the verb señalar.

• yo señalé = I pointed out
• tú señalaste = you pointed out
• él/ella/usted señaló = he/she/you pointed out

The preterite is used because this is seen as a completed action in the past: the teacher pointed out the errors at a specific moment.

If you used the imperfect, señalaba, it would sound more like an ongoing, repeated, or background action.

The accent mark shows where the stress goes: se-ña-LÓ.

It is also important because it helps distinguish forms:

• señalo = I point out / I am pointing out
• señaló = he/she pointed out

So the accent is not optional here. It changes both the pronunciation and the meaning.

Ñ is pronounced like ny in canyon.

So señaló sounds approximately like:

• seh-nya-LO

In Spain, this pronunciation is the same as in most other varieties of Spanish. The key thing is that ñ is its own letter and sound, not just an n.

Because dos errores means two errors, an indefinite quantity.

In Spanish, just like in English, you usually do not add the when you simply mean a number of things:

• señaló dos errores = she pointed out two errors

If you wanted to mean the two errors specifically, you would say:

• señaló los dos errores

So:

• dos errores = two errors
• los dos errores = the two errors / both errors

En mi texto means in my text or within my text, which is the natural idea here: the errors are located inside the text.

• en = in, on, within
• de = of, from

So:

• dos errores en mi texto = two errors in my text

If you said de mi texto, it would suggest from my text or of my text, which is not the normal way to express this idea.

In Spanish, possessive adjectives like mi, tu, su, nuestro normally replace the article.

So you say:

• mi texto = my text
• tu libro = your book
• su casa = his/her/their house

Not:

• el mi texto

This is different from English only in structure, not in meaning. Think of mi as already doing the job of identifying the noun.

Yes. Spanish often drops subject pronouns and even noun subjects when the context makes them clear.

So if it is already obvious who did it, you could simply say:

• Señaló dos errores en mi texto.

The full version with La profesora is used when you want to state clearly who did the action, or when that information is new or important.

Yes. The most neutral order is:

• La profesora
  • señaló
    • dos errores
      • en mi texto

But Spanish allows some flexibility for emphasis. For example:

• En mi texto, la profesora señaló dos errores.

This puts more focus on in my text.

You could also hear:

• Dos errores señaló la profesora en mi texto.

This is less neutral and sounds more literary or emphatic.

So the original sentence is the most standard and natural order for everyday use.

No. Señalar can mean several related things, including:

• to point at
• to point out
• to indicate
• to mark

In this sentence, it means to point out or to identify errors.

So the teacher is not necessarily physically pointing with a finger. She may simply be identifying the mistakes in the text.

Usually yes, but it depends on context.

• errores = errors, mistakes
• faltas can also mean mistakes, often especially spelling or language mistakes
• fallos can mean faults or errors in some contexts

For a teacher marking writing, both errores and sometimes faltas are common, but errores is a very safe and general choice.

It is perfectly natural, but other words may be used depending on the situation:

• texto = text, written piece
• redacción = composition / written assignment
• trabajo = assignment / piece of work
• escrito = written text/document

So mi texto is correct and natural, but in a school context you might also hear:

• La profesora señaló dos errores en mi redacción.

That would sound especially natural if it was a school composition or essay.