Tengo una cita médica mañana por la tarde.

Because in Spanish, tener is used for many things that English expresses with to have.

So tengo una cita médica literally means I have a medical appointment.

You would not use ser or estar here, because you are not describing what you are or where you are. You are saying that you have an appointment.

• tengo = I have
• soy = I am, for identity or permanent characteristics
• estoy = I am, for states or locations

In Spanish, you normally use an article here, just as in English you say a medical appointment.

So:

• Tengo una cita médica = I have a medical appointment

Leaving out una would sound incomplete in standard Spanish.

The article una is feminine singular because cita is a feminine singular noun.

Because médica agrees with cita, and cita is feminine.

In Spanish, adjectives usually match the noun in gender and number:

• una cita médica
• un examen médico
• unas visitas médicas

Here, médica does not mean the doctor is female. It simply agrees with cita.

Usually yes, or very close.

Cita médica means medical appointment. It is a general expression for an appointment related to healthcare.

Depending on context, it could mean:

• an appointment with a doctor
• an appointment at a clinic or hospital
• another healthcare-related visit

A very common alternative is:

• Tengo cita con el médico = I have an appointment with the doctor

Both are natural, but una cita médica focuses more on the type of appointment, while cita con el médico focuses more on who the appointment is with.

Because the rest of the sentence makes the meaning clear.

Mañana can mean:

• tomorrow
• morning

But in mañana por la tarde, it cannot mean morning in the afternoon. So here it must mean tomorrow.

So:

• mañana = tomorrow
• por la tarde = in the afternoon

Together: tomorrow in the afternoon.

Por la tarde means in the afternoon.

Spanish often uses por + part of the day for time expressions:

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

So:

• mañana por la tarde = tomorrow afternoon

This is the natural way to say it in Spanish.

Because Spanish does not normally use a preposition before mañana when it means tomorrow.

You simply say:

• mañana = tomorrow
• hoy = today
• ayer = yesterday

Examples:

• Trabajo mañana = I work tomorrow
• Llego hoy = I arrive today
• Fui ayer = I went yesterday

So Tengo una cita médica mañana is perfectly normal.

It is understandable, but Tengo una cita médica mañana por la tarde sounds more natural.

In Spanish, time expressions are often ordered from more general to more specific, or in the order that sounds most natural to native speakers. Here, mañana por la tarde is the standard phrase for tomorrow afternoon.

So the best version is:

• Tengo una cita médica mañana por la tarde

Yes, and in fact that is the most natural choice here.

Spanish usually drops subject pronouns when the verb already shows who the subject is.

• Tengo already tells us it means I have

So:

• Tengo una cita médica mañana por la tarde = natural
• Yo tengo una cita médica mañana por la tarde = also correct, but more emphatic

You might include yo if you want contrast, for example:

• Yo tengo una cita médica, pero él no = I have a medical appointment, but he doesn’t

It can mean both.

Cita can be:

• an appointment
• a date
• an arranged meeting

The context tells you which meaning is intended.

Examples:

• una cita médica = a medical appointment
• una cita con el dentista = a dentist appointment
• una cita romántica = a romantic date

So in this sentence, médica makes the meaning completely clear.

Yes, that is also possible, and native speakers do say it.

Both of these are natural:

• Tengo una cita médica mañana por la tarde
• Tengo cita médica mañana por la tarde

The version with una feels a bit more like I have a medical appointment, while the version without the article can sound slightly more fixed or routine, similar to I have a doctor’s appointment.

For learners, Tengo una cita médica... is a very safe and clear option.

You would change por la tarde to por la mañana.

• Tengo una cita médica mañana por la mañana = I have a medical appointment tomorrow morning

This is correct, even though mañana appears twice with different meanings:

• first mañana = tomorrow
• second mañana in por la mañana = morning

Spanish speakers understand this easily from the structure.

Yes. Tengo is present tense, but Spanish often uses the present to talk about future events, especially planned ones.

So:

• Tengo una cita médica mañana por la tarde

literally uses the present, but it naturally means:

• I have a medical appointment tomorrow afternoon

This is very common in both Spanish and English for scheduled events.

Compare:

• Mañana trabajo = I work tomorrow / I’m working tomorrow
• El lunes tengo examen = I have an exam on Monday

So the present tense here is completely normal.