Learn Hardcore German: Unten am Bach lachen die Kleinen laut und machen die Hosen nass. - Down by the creek the little ones laugh loudly and get their trousers wet.

German main clauses follow the verb‑second (V2) rule: the conjugated verb must be in second position, but anything can be in first position: subject, time, place, etc.

Here, the place expression Unten am Bach is put first for emphasis (it sets the scene), so:

Unten am Bach – first position (adverbial phrase)
lachen – second position (finite verb)
die Kleinen – third position (subject)

If you started with the subject, you’d get:

Die Kleinen lachen unten am Bach laut und machen die Hosen nass.

This is also correct, but it emphasizes who is doing it more than where it happens.

What exactly does am Bach mean, and which case is used here?

am is a contraction of an dem:

an (preposition “at / by / on”)
dem (dative singular masculine/neuter article)

Bach is masculine (der Bach, “stream, brook”), so:

an + dem Bach → am Bach

Because this is a location (“down by the stream”), an takes the dative case. With an, you typically get:

Dative for location (Wo? – where?):
am Bach, an der Wand, am Fenster
Accusative for movement towards (Wohin? – to where?):
an den Bach, an die Wand, ans Fenster

Why is die Kleinen written with a capital K, and what does it mean grammatically?

Kleinen is originally an adjective (klein = “small”), but here it is used as a noun meaning “the little ones” (normally children).

In German:

Adjectives used as nouns are capitalized.
They are declined like adjectives, but behave syntactically as nouns.

So:

die Kleinen = “the little ones” (plural)
Singular would be:
- der Kleine (male: the little boy)
- die Kleine (female: the little girl)

Without an article in the plural, you might see:

Kleine lachen laut. – “Little ones are laughing loudly.”

Capitalization signals that Kleinen is being treated as a noun here.

Why is it lachen die Kleinen and not lacht die Kleinen?

lachen agrees with its subject die Kleinen, which is plural:

die Kleinen → 3rd person plural
Present tense: sie lachen (“they laugh”)

So the correct form is:

Unten am Bach lachen die Kleinen …

If the subject were singular:

der Kleine lacht
die Kleine lacht

Why is laut used here without any ending, and does it work like an adverb?

Yes. In lachen … laut, laut functions as an adverb, describing how they laugh.

In German, most adverbs look like the base form of the adjective, without any extra ending:

laut lachen – to laugh loudly
schnell laufen – to run quickly
schön singen – to sing beautifully

You only add endings when the word is used attributively (directly in front of a noun):

ein lautes Lachen – a loud laugh
Here laut → lautes because it modifies Lachen directly.

In the sentence, laut describes the verb lachen, so it stays in its basic form.

Why is die Hosen in the plural, even though in English we say “their pants” as if it’s one thing?

In German, Hose (trousers) behaves like English pants:

die Hose – one pair of pants (grammatically singular)
die Hosen – trousers in the plural, or multiple pairs depending on context

Native speakers often use the plural when talking about someone’s trousers in a general, everyday way:

Ich habe mir die Hosen schmutzig gemacht. – I got my pants dirty.
Zieh dir die Hosen an! – Put your pants on!

So die Hosen here very naturally means “their pants/trousers”, even if each child is only wearing one pair.

Why is it die Hosen and not ihre Hosen (“their pants”)?

German often uses a definite article (der, die, das) where English uses a possessive (my, his, their), especially with:

body parts
clothing
things that are clearly owned by the subject from context

Examples:

Er wäscht sich die Hände. – He is washing his hands.
Sie zieht sich die Schuhe an. – She is putting her shoes on.

Similarly:

machen die Hosen nass – literally: “make the pants wet”

Because we already know we’re talking about their own pants, German doesn’t need ihre. English, however, needs “their” to make the sentence sound natural: “get their pants wet.”

Why is nass at the very end of the sentence? Could it go somewhere else?

Standard German word order tends to push non‑finite elements (like infinitives and complements) towards the end of the clause.

In machen die Hosen nass:

machen – conjugated verb (in the left part of the sentence)
die Hosen – direct object (accusative)
nass – predicative adjective (a complement describing the state of die Hosen)

The structure is:
[Verb] [Object] [Predicative] → machen die Hosen nass

Putting nass right after Hosen (machen die Hosen nass) is the normal and most natural order. Other orders like machen nass die Hosen are not idiomatic in this sentence.

What is the grammatical role of nass in machen die Hosen nass?

Here, nass is a predicative adjective: it describes the resulting state of the object die Hosen.

The pattern is:

etwas nass machen – to make something wet
etwas sauber machen – to make something clean
etwas schön machen – to make something beautiful

In all these, the adjective (nass, sauber, schön) is not describing the verb but the object after the action has happened. English usually uses the same structure: “make [object] wet/clean/nice.”

Could you also say machen sich die Hosen nass? What’s the difference?

Yes, you can also say:

Unten am Bach machen sich die Kleinen die Hosen nass.

This is a common reflexive pattern:

sich etwas nass machen – literally “to make something wet for oneself”, but idiomatically “to get something wet (of yours)”

Subtle differences:

machen die Hosen nass
Focus: the pants are being made wet.
machen sich die Hosen nass
Emphasizes the children themselves as the ones responsible for getting their own pants wet. It can sound a bit more colloquial or vivid.

Both sentences are grammatically correct and natural; it’s mostly a nuance of style and emphasis.

Is the German present tense lachen / machen here more like “are laughing / are making” or “laugh / make”?

German has one present tense (das Präsens), which covers both:

simple present: they laugh, they make
present progressive: they are laughing, they are making

Context decides which English form you choose. In a narrative about what’s happening right now, you’d usually translate it with the progressive:

… lachen die Kleinen laut und machen die Hosen nass.
→ “… the little ones are laughing loudly and getting their pants wet.”

If it were a general statement (habit), you might choose simple present in English, but here it’s clearly a current scene.

Is Unten here an adverb, and how is it different from unter?

Yes, unten is an adverb of place meaning “down / down below”.

unten – “down” as a location:
Unten am Bach – down by the stream
Er wartet unten. – He is waiting downstairs / down there.

unter is a preposition meaning “under / below”, and it requires a noun and a case:

unter dem Tisch – under the table
unter der Brücke – under the bridge

So:

unten = standalone adverb (“down there”)
unter = preposition that needs an object (“under something”)

Could the word order be Unten am Bach lachen laut die Kleinen? Would that be correct?

Grammatically, Unten am Bach lachen laut die Kleinen is possible, but it sounds unusual and a bit awkward in everyday German.

More natural variants:

Unten am Bach lachen die Kleinen laut und machen die Hosen nass.
(adverbial – verb – subject – adverb)
Unten am Bach lachen die Kleinen und machen laut die Hosen nass.
(if you really wanted to stress laut with machen, but still sounds less natural)

German tends to keep subject and finite verb close together when possible, and free adverbs like laut normally follow after subject and verb, not inserted between verb and subject. So the original sentence is stylistically the best version.