Learn Hardcore Czech: Když ale běhám moc rychle, bolí mě celé tělo. - But when I run too fast, my whole body hurts.

Ale když běhám moc rychle, bolí mě celé tělo.
– This starts with ale and sounds like a more direct contrast to the previous sentence, similar to “But when I run too fast…”
Když ale běhám moc rychle, bolí mě celé tělo.
– Here, když introduces the time/condition, and ale is inserted for contrast, a bit like “When, however, I run too fast…” (although in English we normally wouldn’t say it that way).

In practice, Když ale… is very natural spoken Czech. Ale když… is also natural; the difference is more about rhythm and subtle emphasis than strict grammar. Both are fine in everyday language.

Why is it běhám and not běžím? Aren’t both “I run”?

Czech has aspect: verbs often come in imperfective/perfective pairs.

běhat – to run (in general, habitually, repeatedly) → běhám = I run (regularly, habitually, whenever)
běžet – to run (this specific act, one time, in progress) → běžím = I am running / I will run (this time)

In Když ale běhám moc rychle, bolí mě celé tělo, we’re talking about what generally happens whenever the speaker runs too fast. That’s why the habitual běhám (from běhat) is used.

If you used běžím, you’d be closer to talking about a specific situation:

Když běžím moc rychle, začne mě píchat v boku.
When I (am) run(ning) too fast, I start to get a stitch in my side.

Even there, though, Czech often still prefers běhám for regular, repeated situations.

What exactly does moc mean here? Is it “too” or “very”? Could I use příliš instead?

In this sentence, moc means “too” (as in “excessively”), not just “very”.

moc rychle → too fast

moc is very common in spoken Czech and is a bit informal. It can mean:

very: Je to moc dobré. – It’s very good.
too (much): Je to moc drahé. – It’s too expensive.

příliš also means “too”, but it is a bit more neutral/formal:

Když ale běhám příliš rychle, bolí mě celé tělo. – perfectly correct, just slightly more formal or careful style.

If you just wanted “very fast” without the idea of “too much”, you’d more likely say:

běhám velmi rychle – I run very fast. (neutral/formal)
běhám fakt / strašně rychle – I run really / incredibly fast. (informal)

How does bolí mě celé tělo work grammatically? Who is the subject and who is the object?

The verb bolet means “to hurt”, but its structure is basically the reverse of English:

bolí mě celé tělo
literally: “hurts me the-whole body”

Grammatically:

celé tělo = subject (nominative; the thing that hurts)
mě = object (accusative; the person who feels the pain)
bolí = 3rd person singular present of bolet

So whereas English says “My whole body hurts” (body = subject), Czech also treats the body as the subject, but adds mě to show whom it hurts:

Bolí mě hlava. – I have a headache. / My head hurts.
(literally “hurts me head”)
Bolí nás nohy. – Our legs hurt.
(literally “hurt us legs”)

So bolí mě celé tělo is best understood as “My whole body hurts (me)”, with celé tělo as subject and mě as the object.

Why is it mě and not mně or já? What’s the difference?

já, mě/mne, mně/mi are forms of the pronoun “I / me” in different cases and styles:

já – nominative (subject): Já běhám. – I run.
mě / mne – accusative (object) or genitive; mě is the usual short form
mně / mi – dative (to me); mi is short, mostly in speech

With bolet, the most common pattern in standard Czech is:

(něco)
- bolí
  - mě (= accusative)
    Bolí mě celé tělo. – My whole body hurts.

You will also hear Bolí mi hlava in spoken Czech (dative), but Bolí mě hlava is more standard, especially in writing.

As for mě vs mne:

mě – normal, everyday form; used almost everywhere in speech and informal writing
mne – more formal, emphatic, or poetic; or after some prepositions in careful style

You could say Bolí mne celé tělo, but it sounds more formal or old‑fashioned.

Why is it celé tělo and not celý tělo or celá tělo?

The adjective must agree in gender, number, and case with the noun.

tělo = neuter, singular (nominative here)
The correct form of celý for neuter singular nominative is celé.

So the patterns are:

masculine inanimate: celý stůl – the whole table
feminine: celá kniha – the whole book
neuter: celé tělo – the whole body

That’s why celé tělo is correct: celé (neuter) matches tělo (neuter).

Can I move the words around, like Když ale moc rychle běhám, celé tělo mě bolí? How flexible is the word order?

Czech word order is quite flexible, and several variants are possible and correct. Each version slightly changes the emphasis, not the basic meaning.

Some natural options:

Když ale běhám moc rychle, bolí mě celé tělo.
– neutral; new information at the end: my whole body hurts.
Když ale běhám moc rychle, celé tělo mě bolí.
– puts celé tělo earlier; emphasizes the whole body (not just one part).
Když ale běhám moc rychle, bolí celé tělo mě.
– grammatical, but unusual; sounds marked/poetic or very emphatic on mě (“it’s me whose whole body hurts”).
You can also move moc rychle:
Když ale moc rychle běhám, bolí mě celé tělo.
– sounds fine; slight rhythmic change, similar meaning.

So yes, you can say Když ale moc rychle běhám, celé tělo mě bolí, and it’s natural Czech. The default neutral version many learners start with is the original: … bolí mě celé tělo.

Could I drop mě and just say … bolí celé tělo? Would it still mean “my whole body hurts”?

Technically you can say Bolí celé tělo, but:

Bolí celé tělo. by itself sounds like a general statement:
“The whole body hurts.” (whose body? not clear from the sentence)
Bolí mě celé tělo. clearly means “My whole body hurts.”

In everyday Czech, with body parts and feelings, the personal pronoun (mě, mi, tě, mu…) is usually present. The possessive pronoun is usually omitted:

Bolí mě hlava. – literally “Hurts me head” → I have a headache.
Not usually Moje hlava mě bolí, except for strong emphasis.

So in this sentence, mě is very natural and helps signal that it’s me who feels the pain.

Why is there a comma before bolí? How does punctuation work with když in Czech?

Když introduces a subordinate clause (a dependent clause). In Czech, when a subordinate clause comes before the main clause, you normally separate them with a comma.

Structure here:

Subordinate clause: Když ale běhám moc rychle – When I run too fast
Main clause: bolí mě celé tělo – my whole body hurts

So you get:

Když ale běhám moc rychle, bolí mě celé tělo.

If you reverse the order, you still use a comma:

Bolí mě celé tělo, když běhám moc rychle.

In short: když‑clause + comma + main clause is the standard pattern in Czech.

How should I pronounce běhám, moc, rychle, bolí, and tělo? Anything important to watch out for?

Key points for each word:

běhám – [ˈbjɛɦaːm]
- ě after b is pronounced roughly like bje: bje-hám.
- á is a long vowel; hold it longer than a.
moc – [mots]
- Final c is pronounced like ts, not like English “k”: mots.
rychle – [ˈrɪx.lɛ]
- ch is a voiceless velar fricative , like the ch in German Bach or Scottish loch.
- The r is rolled/trilled.
bolí – [ˈboliː]
- í is a long ee sound; again, noticeably longer than short i.
tělo – [ˈcɛlo]
- tě is pronounced like soft ťe, which sounds somewhat like tye with the tongue touching further forward and the sound softer; in IPA it’s [cɛ].
- Both vowels are short.

Czech stress is always on the first syllable of the word, so:

BĚ‑hám, MOC, RYCH‑le, BO‑lí, TĚ‑lo.