Learn Hardcore German: Wenn mir der Hals weh tut, trinke ich Tee und fühle mich schnell wieder wohl. - When my throat hurts, I drink tea and soon feel comfortable again.

But mir tut der Hals weh (or Wenn mir der Hals weh tut) is very idiomatic and common, especially when talking about parts of your own body or general pain:
Mir tut der Kopf weh. / Mir tun die Beine weh.

What exactly does weh tun mean, and how does this verb work?

weh tun means to hurt (to cause pain). The infinitive is written as one word: wehtun. It is a separable verb, so in most tenses and clauses it splits:

Präsens:
- es tut weh – it hurts
- es tut mir weh – it hurts me
- mein Hals tut mir weh / mir tut der Hals weh
Präteritum (simple past):
- es tat weh – it hurt
Perfekt (present perfect):
- es hat wehgetan – it has hurt / it hurt

Pattern with people and body parts:

jemandem (dative) tut / tun etwas weh
- Mir tun die Augen weh.
- Ihm tut der Rücken weh.

Why is the verb at the end in Wenn mir der Hals weh tut?

Wenn introduces a subordinate clause (a dependent clause). In German subordinate clauses, the conjugated verb goes to the end of the clause.

Structure here:

Wenn (subordinating conjunction)
mir (dative pronoun)
der Hals (subject)
weh (separable part)
tut (conjugated verb at the end)

So the rule is:

Subordinate clause: conjunction … all other elements … verb at the end
Wenn mir der Hals weh tut, …

In contrast, the main clause that follows has normal verb‑second word order:

…, trinke ich Tee … (verb = trinke in second position)

Why is there a comma before trinke ich Tee, and why is the word order different there?

The comma separates a subordinate clause from a main clause:

Subordinate clause: Wenn mir der Hals weh tut,
Main clause: trinke ich Tee und fühle mich schnell wieder wohl.

Rules:

Comma:
In German, a comma is required between a subordinate clause and the main clause.
Word order in the main clause:
German main clauses follow verb‑second (V2) word order:
- First position: either the subject or some other element (here, the whole Wenn… clause sits in position 1)
- Second position: the conjugated verb

Because the Wenn‑clause takes the first position, the main clause starts with the verb:

Wenn mir der Hals weh tut, trinke ich Tee.
(conjugated verb trinke is in the second position of the overall sentence, after the whole wenn‑clause)

If you reversed the order, you’d get:

Ich trinke Tee, wenn mir der Hals weh tut.
Now ich is in first position and trinke is in second.

What is the role of mich in fühle mich? Why can’t I just say ich fühle wohl?

sich fühlen is a reflexive verb in German when it means to feel (in a certain condition):

ich fühle mich
du fühlst dich
er / sie fühlt sich
wir fühlen uns, etc.

So:

Ich fühle mich wohl. = I feel well / I feel comfortable.

Without the reflexive pronoun, fühlen usually means to feel/sense something (an object):

Ich fühle den Schmerz. – I feel the pain.
Ich fühle die Kälte. – I feel the cold.

So:

Ich fühle wohl. is wrong in standard German.
You must say Ich fühle mich wohl. (I feel well / comfortable).

What is the difference between wohl and gut in this sentence?

Both relate to feeling good, but the nuance is slightly different:

Ich fühle mich wohl.
- Focus: being comfortable, at ease, not in pain, relaxed, in a pleasant state.
- Often used for physical and emotional comfort: I feel good / comfortable / at ease.
Ich fühle mich gut.
- More neutral; can mean I feel healthy or I feel good in a generic way.
- Often used in contrast to being ill or unwell.

In the context of being sick / sore throat, wohl is very idiomatic:

… und fühle mich schnell wieder wohl.
implies: I soon feel comfortable/okay again (no longer bothered by the sore throat).

Why is it fühle mich schnell wieder wohl and not fühle mich wohl schnell wieder?

The cluster mich wohl belongs closely together: mich is the reflexive pronoun, wohl is the predicative (describing how you feel). Adverbs like schnell and wieder usually go between the verb and what they modify.

Natural order:

fühle mich schnell wieder wohl

Breakdown:

fühle (verb)
mich (reflexive pronoun)
schnell (adverb: quickly)
wieder (adverb: again)
wohl (state/predicate: well, comfortable)

Other slightly less common but still acceptable variants:

fühle mich wieder schnell wohl (similar meaning, different emphasis)

But:

fühle mich wohl schnell wieder sounds wrong because wohl is pushed away from mich and left at the end, which disrupts the natural grouping mich wohl.

Why are Hals and Tee capitalized?

In German, all nouns are capitalized, regardless of where they appear in the sentence.

der Hals – the throat (noun)
Tee – tea (noun)

So you always write:

der Hals, mein Hals
der Tee, Tee trinken

Adjectives, verbs, and adverbs are usually lowercase (except at the beginning of a sentence or when they are turned into nouns).

Does wenn here mean if or when? Could I use als instead?

In this sentence, wenn can be understood as both if and whenever/when, and that’s normal:

Wenn mir der Hals weh tut, trinke ich Tee …
= If my throat hurts, I drink tea …
or
= Whenever my throat hurts, I drink tea …

You cannot use als here, because:

als is used for:
- a single, specific event in the past
  - Als ich krank war, habe ich Tee getrunken. – When I was ill (that time), I drank tea.
wenn is used for:
- repeated actions / general conditions (present, past, future)
- real conditions (if/whenever)

Your sentence describes a general habit, not one single event in the past, so wenn is correct and als would be wrong.

Can I also say Wenn mir der Hals weh tut, dann trinke ich Tee?

Yes, that is perfectly correct and very natural.

Wenn mir der Hals weh tut, trinke ich Tee.
Wenn mir der Hals weh tut, dann trinke ich Tee.

dann emphasizes the consequence (then), but the basic meaning is the same.

Note on word order:

Wenn mir der Hals weh tut, dann trinke ich Tee.
Here dann is in the first position of the main clause, and trinke is still in the second position, which keeps the verb‑second rule:
- (1) dann – (2) trinke – (3) ich Tee

Why do we say weh tut and not write it as one word?

The infinitive is wehtun (one word), and it is a separable verb. In finite forms in main and many subordinate clauses, the stressed part weh is separated and moved to the end:

Infinitive: wehtun
Präsens:
- es tut weh (not: tutweh)
Perfekt:
- es hat wehgetan (prefix attached to the past participle)

In your sentence (which is a subordinate clause), word order is:

… der Hals weh tut
subject – prefix – verb.

Writing *wehtut or tutweh as one word in this position is incorrect in standard German.

What is the difference between mir in mir der Hals and mich in fühle mich?

mir and mich are both forms of ich (I), but they are different cases:

mir = dative (to me / for me)
mich = accusative (me, as a direct object or reflexive)

In your sentence:

Wenn mir der Hals weh tut, …
- mir = dative: the person who experiences the pain
- Pattern: jemandem (dative) tut etwas weh
  literally: the throat hurts to me
… und fühle mich schnell wieder wohl.
- mich = accusative reflexive pronoun
- Pattern: sich fühlen = to feel (in some state)
- ich fühle mich = I feel myself (in some condition), here: wohl

So:

Use mir when you are an indirect/experiencer object (something happens to you):
Mir ist kalt. (I am cold / It is cold to me.)
Mir tut der Rücken weh.
Use mich when you are a direct/reflexive object:
Ich wasche mich. – I wash myself.
Ich fühle mich gut. – I feel good.