En clase, la profesora nos recordó que un verbo cambia de forma según la persona y el tiempo.

Yes. En clase commonly means in class, during class, or in the classroom context.

In this sentence, it works like a setting phrase: it tells you where/when this happened before giving the main action.

• En clase, la profesora nos recordó... = In class, the teacher reminded us...

Spanish often puts this kind of phrase at the beginning for context, just like English can.

Both can exist, but they do not always mean the same thing.

• En clase usually means in class / during class in a general sense.
• En la clase more often means in the classroom or in the specific class.

So here, En clase sounds natural because the sentence is talking about what happened during class time, not pointing to one specific classroom as a physical place.

Compare:

• En clase hablamos español. = In class we speak Spanish.
• En la clase hay veinte sillas. = There are twenty chairs in the classroom.

Spanish uses articles more often than English does.

Here, la profesora means the teacher. It refers to a specific teacher that the speaker and listener both know about.

In English, we often say just the teacher, but in Spanish the article is very normal and usually required:

• La profesora explicó la lección.
• El estudiante llegó tarde.

If you said just profesora here, it would sound incomplete.

Nos means us.

It is an object pronoun, and in this sentence it tells you who was reminded:

• la profesora nos recordó = the teacher reminded us

So the structure is:

• la profesora = subject, the person doing the action
• nos = object, the people receiving the reminder
• recordó = reminded

Because in Spanish, object pronouns normally go before a conjugated verb.

So:

• nos recordó
• me dijo
• te explicó
• les enseñó

This is the standard position with normal finite verb forms.

You only attach pronouns to the end in certain cases, such as:

• infinitives: recordarnos
• gerunds: recordándonos
• affirmative commands: recuérdanos

But with recordó, a conjugated past tense form, the pronoun goes before it: nos recordó.

Recordó is the preterite of recordar in the third person singular.

That means:

• infinitive: recordar
• tense: preterite
• person: él / ella / usted
• form: recordó

Here it matches la profesora, so:

• la profesora recordó = the teacher reminded / remembered

In this sentence, the preterite is used because it refers to a completed action in the past: at some point in class, she reminded them.

It can mean both, depending on the structure.

In this sentence, it means to remind.

• Recordé la respuesta. = I remembered the answer.
• La profesora nos recordó que... = The teacher reminded us that...

A useful pattern is:

• recordar algo = to remember something
• recordarle algo a alguien / recordarnos algo = to remind someone of something

So here, because there is nos and then a clause with que, the meaning is clearly reminded us that...

Because que introduces the idea or statement that follows the verb remind.

• nos recordó que... = reminded us that...

This is very common in Spanish after verbs like:

• decir que = to say that
• explicar que = to explain that
• recordar que = to remind that
• creer que = to believe that

So que here simply links the main verb to the following clause:

• un verbo cambia de forma según la persona y el tiempo

Because un verbo is being used in a general, explanatory sense: a verb as a type of word.

The sentence is stating a general grammar fact:

• un verbo cambia de forma... = a verb changes form...

Spanish often uses the singular with an indefinite article to talk about something in general, especially in explanations and definitions.

You could also see:

• Los verbos cambian de forma... = Verbs change form...

That would also be correct, but it would be phrased more generally in the plural.

Cambiar de forma means to change form or to change shape/form.

In grammar, it means that the verb takes different forms depending on person and tense.

The de is part of the expression:

• cambiar de nombre = to change name
• cambiar de color = to change colour
• cambiar de forma = to change form

So Spanish uses cambiar de + noun in many cases where English might simply say change + noun or change in + noun.

Here it refers to conjugation:

• hablo, hablas, habla
• comí, comiste, comió

These are different forms of a verb.

Según means according to, depending on, or depending on the basis of.

In this sentence:

• según la persona y el tiempo = depending on the person and the tense

So the sentence is saying that the form of a verb changes depending on those grammatical categories.

It is a very useful word:

• Según el profesor, el examen será fácil. = According to the teacher, the exam will be easy.
• Según el contexto, puede significar otra cosa. = Depending on the context, it can mean something else.

They are grammatical terms, not everyday meanings.

• la persona = grammatical person
  That means:

  • first person: yo / nosotros
  • second person: tú / vosotros / usted / ustedes
  • third person: él / ella / ellos / ellas

• el tiempo here means tense For example:

  • present: hablo
  • preterite: hablé
  • imperfect: hablaba
  • future: hablaré

So the sentence means that verbs change form according to:

1. who is doing the action
2. when the action happens

Because Spanish is referring to the categories in a general, abstract way.

• la persona = the grammatical category of person
• el tiempo = the grammatical category of tense

This is similar to English when we say:

• according to person and tense
• depending on number and gender

Spanish often uses the singular when talking about a category as a concept.

You could also find plural wording in other contexts, but the singular here is completely natural.

Because the clause after que expresses a general truth about grammar.

The teacher reminded them of a fact that is still true:

• un verbo cambia de forma según la persona y el tiempo

That is a general rule, so Spanish uses the present tense.

This is common after a past verb when the thing being said is still valid:

• El profesor explicó que la Tierra gira alrededor del Sol.
• Nos dijeron que el agua hierve a 100 grados.

The main action is in the past (recordó), but the fact itself remains true, so the present is natural.

The comma separates the introductory phrase from the main clause.

• En clase, la profesora nos recordó...

This is similar to English writing:

• In class, the teacher reminded us...

In short sentences, some commas around introductory phrases can be optional depending on style, but this comma is perfectly normal and helps readability.

Yes. Spanish is more flexible with word order than English, although some versions sound more natural than others.

For example:

• La profesora nos recordó en clase que un verbo cambia de forma según la persona y el tiempo.

This is also correct. It just places en clase later.

Starting with En clase puts the classroom context first, which feels natural if that is the setting the speaker wants to highlight.

In Spanish, profesor/profesora often means teacher in a broad sense, not only university professor.

So in many school contexts:

• la profesora = the teacher

Depending on context, it can sometimes be translated as professor, but for a sentence like this, teacher is usually the most natural translation.

Not much in this particular sentence. It is standard Spanish that would be understood across the Spanish-speaking world.

One small point is that it avoids region-specific features, so it is very neutral. There is no vosotros, no region-specific vocabulary, and nothing especially colloquial.

So this sentence works well as standard Spanish, including Spanish from Spain.