Learn Hardcore Spanish (Spain): Mi madre quiere vacunar a mi hermana contra la gripe. - My mother wants to vaccinate my sister against the flu.

You do not conjugate both verbs (“quiere vacuna” or “quiere vacuna a” are wrong). Only querer is conjugated; vacunar stays in the infinitive.

Why do we say vacunar a mi hermana with a, and not vacunar mi hermana?

The a is the “personal a”, which Spanish uses for direct objects that are people (and often pets):

Vacunar a mi hermana – to vaccinate my sister
Ayudo a mi madre. – I help my mother.
Veo a Juan. – I see Juan.

So:

Mi madre quiere vacunar a mi hermana... ✅
Mi madre quiere vacunar mi hermana... ❌ (incorrect in standard Spanish)

We do not add the personal a in front of mi madre because mi madre is the subject, not the object.

Could we replace a mi hermana with a pronoun, like Mi madre quiere vacunarla?

Yes. With direct object pronouns, you have two correct options when there’s an infinitive:

Attach the pronoun to the infinitive (enclitic):
- Mi madre quiere vacunarla contra la gripe.
Put the pronoun before the conjugated verb:
- Mi madre la quiere vacunar contra la gripe.

Both mean: My mother wants to vaccinate her against the flu.

Notes:

la refers to mi hermana (feminine singular).
You cannot say “Mi madre quiere la vacunar” ❌ — the pronoun must go either:
- before quiere (la quiere vacunar), or
- attached to vacunar (vacunarla).

What is the difference between vacunar a alguien and vacunarse?

vacunar a alguien = to vaccinate someone (you vaccinate another person)
- El médico va a vacunar a los niños. – The doctor is going to vaccinate the children.
vacunarse = to get vaccinated / to be vaccinated oneself (reflexive)
- Mi madre quiere vacunarse. – My mother wants to get vaccinated.

Compare:

Mi madre quiere vacunar a mi hermana.
My mother wants to vaccinate my sister. (my mother acts on my sister)
Mi madre quiere vacunarse.
My mother wants to get herself vaccinated. (my mother is the one receiving the vaccine)

So the reflexive -se changes the meaning from “do to someone else” to “have done to oneself”.

Why is it contra la gripe? Could we say de la gripe or para la gripe?

With vacunar, the most standard options in Spain are:

vacunar contra la gripe – vaccinate against the flu
vacunar de la gripe – vaccinate against the flu (also common, especially in Spain)

Both are used, and both are understood as “against the flu”.

para la gripe is not normally used here; it would sound odd.
contra literally means against, which fits the idea of protection.
de in this context is an older/established usage meaning protection from something.

So you can also hear:

Mi madre quiere vacunar a mi hermana de la gripe. ✅
(completely natural in Spain)

Why do we use the article la with gripe? Can we say just contra gripe?

In Spanish, names of illnesses usually take the definite article:

la gripe – the flu
el COVID, el cáncer, el resfriado

So:

contra la gripe ✅ (normal)
contra gripe ❌ (sounds wrong/very foreign)

In general statements, Spanish still tends to keep the article, even though English often drops “the”:

Vacunarse contra la gripe es importante.
Getting vaccinated against flu is important. (Eng. often says “against flu”, but Spanish keeps la.)

You might see the article dropped in headlines or very telegraphic language, but in normal speech and writing, use the article.

Can we change the word order, for example:
Mi madre quiere vacunar a mi hermana contra la gripe → Mi madre quiere vacunar contra la gripe a mi hermana?

Yes, you can say:

Mi madre quiere vacunar contra la gripe a mi hermana. ✅

This is grammatically correct. The difference is mostly in rhythm and slight emphasis:

Mi madre quiere vacunar a mi hermana contra la gripe.
Neutral, the most typical order (S–V–O + complement).
Mi madre quiere vacunar contra la gripe a mi hermana.
Puts a bit more focus on contra la gripe by bringing it closer to vacunar.

What you typically wouldn’t do is scatter the pieces unnaturally, e.g.:

Mi madre quiere contra la gripe vacunar a mi hermana ❌ (sounds very odd).

Spanish word order is flexible, but you still usually keep: subject – conjugated verb – infinitive – object – complements, unless you want a specific emphasis.

Why is it mi madre and mi hermana, not la madre / la hermana?

With close family members (mother, father, brother, sister, etc.) in the singular, Spanish very often uses a possessive adjective:

mi madre, mi padre, mi hermana, mi hermano

Using la madre / la hermana would normally mean:

“the mother / the sister” in a more generic or context-dependent sense, not clearly “my”.

For example:

La madre de Juan está aquí. – Juan’s mother is here.
Mi madre está aquí. – My mother is here.

In your sentence, the focus is “my mother” and “my sister”, so mi madre / mi hermana are the natural forms.

Could we say Mi madre quiere vacunar a su hermana instead of a mi hermana?

Yes, but it would usually mean something different:

Mi madre quiere vacunar a mi hermana.
My mother wants to vaccinate my sister (the speaker’s sister).
Mi madre quiere vacunar a su hermana.
My mother wants to vaccinate her sister → that is, my aunt.

In Spanish, su normally refers to the third person’s possession (his/her/their).
So su hermana in that sentence refers to mi madre’s sister, not mine.

If you want to be 100% clear that it is your sister as the speaker, keep mi hermana.

Does quiere vacunar mean she is definitely going to vaccinate her, or just that she would like to?

Quiere vacunar literally means “wants to vaccinate” – it expresses a desire or intention, not a certainty.

Mi madre quiere vacunar a mi hermana contra la gripe.
My mother wants to vaccinate my sister against the flu. (She intends/would like to do it.)

If you want to emphasize that it is already arranged or about to happen, you would typically use something else, e.g.:

Mi madre va a vacunar a mi hermana... – My mother is going to vaccinate my sister...
Mi madre tiene que vacunar a mi hermana... – My mother has to vaccinate my sister...

So querer + infinitive in Spanish is about wanting, not a firm future plan by itself.

What exactly does gripe mean in Spain? Is it the same as a cold?

In Spain:

la gripe = the flu (influenza), a stronger viral infection, often with high fever, muscle pain, etc.
el resfriado or el catarro = a (common) cold, usually milder: runny nose, sore throat, maybe low fever.

So:

Your sentence is specifically about a flu vaccine, not just a general cold remedy.

How would we say that my mother wants to get herself vaccinated, not my sister?

Use the reflexive form vacunarse:

Mi madre quiere vacunarse contra la gripe.
My mother wants to get vaccinated against the flu.

Other examples:

Quiero vacunarme. – I want to get vaccinated.
Nos vamos a vacunar. – We’re going to get vaccinated.

In all of these, the person is both the “doer” and the one receiving the vaccine.

Are there any important pronunciation points in this sentence?

Yes, a few helpful ones:

Mi madre:
- madre has the stress on the first syllable: MA-dre.
- The d between vowels is soft, not a hard “d”; it’s closer to the English “th” in this.
quiere:
- Pronounced roughly KYER-eh.
- The qu before ie sounds like k in key; u is silent.
vacunar:
- Stress on the last syllable: va-cu-NAR.
- Clear b/v sound at the start (in Spanish, b and v sound the same).
hermana:
- The h is silent: er-MA-na.
- Stress on the middle syllable: her-MA-na.
gripe:
- g before r is like a hard g in green (not like George).
- Stress on the first syllable: GRI-pe.
gripe and quiere both use a single r (tap sound), not the rolled rr.

Saying the sentence with correct stress:

Mi MAdre QUIEre vacuNAR a mi herMAna CONtra la GRIpe.