Por la mañana, me cepillo los dientes y luego desayuno con mi familia.

In Spain, por la mañana is the normal way to say in the morning.

• por la mañana = in the morning
• por la tarde = in the afternoon / evening
• por la noche = at night / in the evening

A learner might expect en la mañana because English uses in, but Spanish usually uses por in this time expression.

Also, por la mañana often means in the mornings or during the morning, depending on context.

The comma is used because Por la mañana is an introductory time phrase. In English, we often do the same:

• In the morning, I brush my teeth...

The sentence would still be understandable without the comma, but the comma makes it clearer and more natural in writing.

Because the verb here is cepillarse, a reflexive verb.

• cepillar = to brush
• cepillarse = to brush oneself

So:

• me cepillo = I brush myself / I brush my own...

In this sentence, Spanish uses the reflexive because the action is being done to the speaker’s own body.

The reflexive pronouns are:

• me = myself
• te = yourself
• se = himself / herself / yourself / themselves
• nos = ourselves
• os = yourselves (used in Spain)
• se = themselves

So:

• Me cepillo los dientes = I brush my teeth

This is a very common Spanish pattern. With body parts, Spanish often uses:

• a reflexive pronoun
  • definite article

instead of a possessive adjective.

So Spanish says:

• me cepillo los dientes literally: I brush myself the teeth

But in natural English, we say:

• I brush my teeth

This same pattern appears in many sentences:

• Me lavo las manos = I wash my hands
• Se toca la cabeza = He/She touches his/her head
• Nos cepillamos el pelo = We brush our hair

Spanish prefers el/la/los/las here because the reflexive pronoun already shows whose body part it is.

Spanish often leaves out subject pronouns because the verb ending already tells you who the subject is.

• cepillo = I brush
• desayuno = I have breakfast

So yo is not necessary.

You could say:

• Yo me cepillo los dientes y luego desayuno con mi familia

But this sounds more emphatic, as if you are stressing I. Most of the time, Spanish simply omits yo.

Both are in the present tense, first person singular:

• cepillo = I brush
• desayuno = I have breakfast / I eat breakfast

In a sentence like this, the present tense usually describes a habit or routine, not just what is happening right now.

So the idea is:

• In the morning, I brush my teeth and then I have breakfast with my family.

That is why this kind of sentence is very common when talking about daily routines.

Good question. Desayuno can be either a noun or a verb form, depending on context.

As a noun:

• el desayuno = breakfast

As a verb:

• desayuno = I have breakfast / I eat breakfast
  (from desayunar = to have breakfast)

In this sentence, it is clearly a verb because it comes after y luego and is part of the action sequence:

• me cepillo los dientes y luego desayuno...
• I brush my teeth and then I have breakfast...

So here desayuno is not the noun breakfast, but the verb I have breakfast.

Yes. Luego and después can both mean then or afterwards.

So these are both natural:

• ...y luego desayuno con mi familia
• ...y después desayuno con mi familia

In Spain, luego is very common in everyday speech.
Both are correct, but luego often sounds especially natural in simple sequences of actions.

Because in this sentence, the speaker means with my family, not just with family in a general sense.

• con mi familia = with my family

Spanish uses the possessive mi here because familia is not a body part or something already shown by a reflexive pronoun. The speaker needs to specify whose family.

If you said con la familia, it would usually mean with the family in a more specific or contextual sense, not necessarily my family.

Because familia is a collective noun. It is grammatically singular, even though it refers to a group of people.

So Spanish says:

• mi familia = my family

not

• mis familias unless you literally mean more than one family

This works the same way in English: family is usually singular as a noun, even though it refers to multiple members.

It can do either, depending on context, but in a sentence like this it usually describes a habitual routine.

So:

• Por la mañana, me cepillo los dientes y luego desayuno con mi familia.

usually means something like:

• In the morning / In the mornings, I brush my teeth and then have breakfast with my family.

If you wanted to make the habitual idea even clearer, you could also say:

• Por las mañanas... = in the mornings

Both are common, but por la mañana is very often used for daily routine statements.

The dictionary forms are:

• cepillarse = to brush oneself
• desayunar = to have breakfast

In the sentence, they appear as:

• me cepillo = I brush myself / I brush my teeth
• desayuno = I have breakfast

It is useful to learn cepillarse with the reflexive se, because that is how it is commonly used when talking about personal care.

It would be:

• Por la mañana, yo me cepillo los dientes y luego desayuno con mi familia.

This is grammatically correct, but it sounds more emphatic. It might suggest:

• As for me, I brush my teeth...
• or a contrast, like I do this, maybe unlike someone else

Normally, Spanish prefers the version without yo unless there is a reason to stress the subject.