La dentista me dijo que tomara una pastilla si la muela me seguía doliendo.

Because dentista is a common-gender noun in Spanish: the noun itself stays the same, and the article shows whether the person is male or female.

• el dentista = the male dentist
• la dentista = the female dentist

So la dentista tells you the dentist is a woman.

Me means to me.

• dijo = said / told
• me dijo = told me / said to me

So La dentista me dijo... means the dentist told me something.

Spanish usually does not copy the English pattern told someone to do something directly.

In Spanish, reported instructions, advice, or commands are often expressed as:

• decir(le) a alguien que + subjunctive

So:

• Me dijo que tomara una pastilla = She told me to take a tablet/pill

A structure like me dijo tomar una pastilla would not be correct here.

Because tomara is the imperfect subjunctive, and it is used here after dijo que to report what someone told or advised the speaker to do.

The idea is not that the action happened already, but that it was something the dentist wanted the speaker to do later, if necessary.

• tomó = she took
• tomé = I took
• tomaría = I would take
• tomara = I should take / was told to take

So me dijo que tomara una pastilla means she told me to take a pill.

Because this is not just reporting information; it is reporting advice, instruction, or a command.

Compare:

• Me dijo que estaba cansada = She told me she was tired

  • Here you would use the indicative, because it is reported information.

• Me dijo que tomara una pastilla = She told me to take a pill

  • Here you use the subjunctive, because it is reported advice/instruction.

So the subjunctive appears because the dentist was telling the speaker what to do.

Yes. Tomara and tomase are both valid imperfect subjunctive forms.

• que tomara
• que tomase

In modern Spanish, -ra forms are more common in everyday speech, but both are correct.

Because after si in a real or open condition, Spanish normally uses the indicative, not the subjunctive.

Here the meaning is basically:

• if my tooth kept hurting

That is a possible real situation from the past point of view, so seguía (imperfect indicative) is correct.

You would use the subjunctive after si in other kinds of unreal or unlikely conditions, for example:

• Si me siguiera doliendo, iría otra vez = If it were still hurting me, I would go again

But in your sentence, the condition is simply the circumstance under which the speaker should take the pill.

Both are possible in some contexts, but seguir + gerundio adds the idea of continuing.

• me dolía = it hurt / was hurting me
• me seguía doliendo = it was still hurting me / it kept hurting me

So seguía doliendo emphasizes that the pain was continuing.

Because the imperfect is used for an ongoing, background, or continuing situation in the past.

The dentist’s advice refers to a possible continuing situation:

• if the tooth was still hurting
• if the pain continued

That is why seguía fits well. A preterite form like siguió would sound more like a completed event, which is not the idea here.

Because doler works like gustar in its structure.

Spanish expresses this as:

• the tooth hurts me

So:

• la muela = the thing causing pain
• me = the person affected
• dolía / seguía doliendo = was hurting / kept hurting

That is why Spanish says:

• La muela me dolía
• literally: The tooth was hurting me

Even though in English we usually say my tooth hurt.

Because doler does not usually work like a normal transitive verb such as romper or comer.

The painful thing is the grammatical subject:

• La muela me dolía = The tooth hurt me

Not:

• Yo dolía la muela ❌

This is the same pattern as:

• Me gusta el café = Coffee pleases me / I like coffee
• Me duele la cabeza = My head hurts / My head hurts me

Diente means tooth in general.

Muela usually means a molar, one of the larger back teeth used for grinding.

So this sentence is more specific than just saying diente. Depending on the context, it may be translated as:

• tooth
• molar

In everyday English, many people would still just say tooth.

Because the sentence means a pill/tablet, not a specific previously identified one.

• una pastilla = a pill / a tablet
• la pastilla = the pill / the tablet

Using una here sounds natural when the dentist is giving general advice: take a pill if the tooth keeps hurting.

It can mean either, depending on context. In medical contexts, pastilla is often translated as:

• pill
• tablet

In Spain, pastilla is a very normal everyday word for medication in solid form.

Yes. Spanish allows some flexibility.

For example, these are natural:

• si la muela me seguía doliendo
• si me seguía doliendo la muela

Both mean essentially the same thing. The original version puts la muela earlier, which may sound a bit clearer or more neutral in context.

Not exactly. It is a reported command or instruction.

A direct command from the dentist might be:

• Tome una pastilla si le sigue doliendo la muela.

But once the speaker reports it later, it becomes:

• La dentista me dijo que tomara una pastilla si la muela me seguía doliendo.

So the sentence is not giving the command directly; it is telling us what the dentist said.

Because the whole sentence is being told from a past point of view.

The main verb is past:

• me dijo = she told me

After that, Spanish shifts the following verbs to match that past frame:

• tomara = what I was supposed to do
• seguía doliendo = the condition under which I should do it

So even though the taking of the pill was later than the dentist’s words, it is still future relative to a past moment, which is why Spanish uses these past-form structures.