Wenn ich zu schnell laufe, fange ich an zu schwitzen.

When I run too fast, I start to sweat.

Breakdown of Wenn ich zu schnell laufe, fange ich an zu schwitzen.

• ich: I
• zu: to
• schnell: fast
• laufen: to run
• wenn: when
• zu: too
• anfangen: to start
• schwitzen: to sweat

Questions & Answers about Wenn ich zu schnell laufe, fange ich an zu schwitzen.

Why does the verb laufe go at the end in wenn ich zu schnell laufe?

Because wenn introduces a subordinate clause in German. In subordinate clauses, the conjugated verb normally goes to the end of the clause.

• Main clause word order: Ich laufe zu schnell. (verb in second position)
• Subordinate clause with wenn: wenn ich zu schnell laufe (verb at the end)

So wenn ich zu schnell laufe is grammatically correct subordinate-clause order: subject (ich) → adverb (zu schnell) → verb (laufe at the end).

Why is there a comma between Wenn ich zu schnell laufe and fange ich an zu schwitzen?

In German, you must put a comma between a subordinate clause and the main clause.

• Wenn ich zu schnell laufe, ← subordinate clause
• fange ich an zu schwitzen. ← main clause

So the comma is obligatory here, not optional, because wenn creates a subordinate clause.

Why is wenn used here and not als or wann?

The three words have different uses:

• wenn

  • means if or whenever
  • used for conditions and repeated events (past, present, or future)
  • Example: Wenn ich müde bin, trinke ich Kaffee. (Whenever / If I am tired, I drink coffee.)

• als

  • used for one specific event in the past
  • Example: Als ich 10 Jahre alt war, hatte ich ein rotes Fahrrad.

• wann

  • means when? in questions (direct or indirect)
  • Example: Wann kommst du? / Ich weiß nicht, wann er kommt.

Your sentence describes a general condition: Whenever / If I run too fast, I start to sweat.
So wenn is the correct choice.

What is the difference between zu schnell and sehr schnell?

• zu schnell = too fast, faster than is good/appropriate; it implies a problem or undesirable level.

  • Example: Das Auto fährt zu schnell. (The car is going too fast – probably dangerous.)

• sehr schnell = very fast, just describing a high speed, not necessarily a problem.

  • Example: Sie rennt sehr schnell. (She runs very fast – neutral or positive.)

In your sentence, zu schnell fits because running too fast causes sweating, which is presented as an unwanted or limiting effect.

What exactly does laufe mean here? Is it “walk” or “run”? Could I say renne instead?

The verb laufen is a bit tricky because its meaning can vary by region and context:

• In Germany, laufen usually leans toward running / jogging.
• In some parts of Switzerland and southern Germany, laufen can also be used more for walking.

In the sentence Wenn ich zu schnell laufe, fange ich an zu schwitzen, the context zu schnell and schwitzen makes laufe sound like run / jog (or at least move quickly).

You can say:

• Wenn ich zu schnell renne, fange ich an zu schwitzen.

This clearly means run too fast.
Rennen is more unambiguously to run (fast), often with the nuance of sprinting or hurrying.

Why is the word order fange ich an and not ich fange an in the second part?

German main clauses follow verb-second (V2) word order: the conjugated verb must be in second position.

The key point: the entire clause Wenn ich zu schnell laufe counts as one single element at the beginning of the whole sentence.

So the structure is:

1. First position: the whole subordinate clause → Wenn ich zu schnell laufe
2. Second position: the finite verb of the main clause → fange
3. Then the subject and the rest → ich an zu schwitzen

So:

• Wenn ich zu schnell laufe, fange ich an zu schwitzen. ✅
• Wenn ich zu schnell laufe, ich fange an zu schwitzen. ❌ (verb is not in second position)

If you start with the subject instead, then it changes:

• Ich fange an zu schwitzen, wenn ich zu schnell laufe. ✅ (now Ich is first, fange is second)

How does anfangen … zu schwitzen work grammatically? Why zu schwitzen and not something like zu anfangen schwitzen?

Several points come together here:

1. anfangen is a separable verb

   • Base form: anfangen
   • In the main clause, it splits: ich fange … an
   • Example: Ich fange morgen an.

2. With another verb in the infinitive, you use zu + infinitive

   • Pattern: anfangen + zu + infinitive
   • Example: Ich fange an zu lesen. (I start to read.)

3. zu goes directly before the infinitive verb that describes the action:

   • zu schwitzen, zu lesen, zu arbeiten, etc.
   • You do not put zu before anfangen in this structure.

So the correct pattern is:

• anfangen
  • zu
    • Verb
• fange ich an zu schwitzen = I start to sweat

Could I also say Ich beginne zu schwitzen instead of Ich fange an zu schwitzen? Is there a difference?

Yes, you can say:

• Wenn ich zu schnell laufe, beginne ich zu schwitzen.

This is grammatically correct and means basically the same thing.

Differences:

• anfangen

  • very common in everyday spoken German
  • separable verb: ich fange an, wir fingen an, ich habe angefangen

• beginnen

  • sounds a bit more formal or neutral
  • often used in written language, instructions, official contexts
  • not separable: ich beginne, wir begannen, ich habe begonnen

In this casual kind of sentence, anfangen is slightly more colloquial and natural, but beginnen is also fine.

Why is the present tense used here for something that feels like a condition (“if I run too fast, I start to sweat”)?

German often uses the present tense for:

• general truths
• habits
• typical consequences

Your sentence describes a general rule: Whenever / If I run too fast, I start to sweat.
This is exactly the kind of thing where German prefers present + present:

• Wenn ich zu schnell laufe, fange ich an zu schwitzen.

You could make other tenses, but they would change the meaning:

• Wenn ich zu schnell laufe, werde ich anfangen zu schwitzen.
  – focus on the future consequence, sounds heavier and less natural here.

• Wenn ich zu schnell liefe, würde ich anfangen zu schwitzen.
  – a hypothetical situation (subjunctive II), like “If I were to run too fast…”

For a normal, general statement, present tense in both clauses is the standard.

Could I replace wenn with falls in this sentence? Would it change the meaning?

You could say:

• Falls ich zu schnell laufe, fange ich an zu schwitzen.

This is grammatically correct, but there is a subtle nuance:

• wenn

  • very common and neutral
  • used for realistic conditions and repeated situations
  • fits well with habitual meaning: whenever / if (as a rule)

• falls

  • more like in case / if by any chance
  • often a bit more formal or used for conditions that are less certain or more hypothetical

In this specific context (your body’s usual reaction), wenn sounds more natural, because it talks about a regular, expected consequence. Falls makes it sound slightly more theoretical.