The present participle as adjective (de lachende man)

The present participle is the Dutch match for the English -ing adjective: de lachende man (the laughing man), kokend water (boiling water). It describes a noun that is doing the action itself.

Add -d to the infinitive; when it sits in front of a noun it then takes -e like any other adjective.

1. Start from the full infinitive, not the stem: lachen (to laugh), koken (to boil/cook), slapen (to sleep).
2. Add -d: lachen → lachend, koken → kokend, slapen → slapend. This is the basic present participle.
3. Before a noun, add the adjective -e where the adjective ending rule calls for it: de lachende man, het slapende kind, huilende kinderen.

Whether the participle takes -e follows the ordinary adjective rules. It gets -e after de/het and in the plural (de lachende man, lachende mensen), but no -e before a het-word with no article — which is why it stays kokend water (see when an adjective takes no -e).

• To describe a noun that is actively doing something: een lopende rekening (a current account), stromend water (running water), een rijdende trein (a moving train).
• As an adverb, describing how something is done: Ze liep zingend naar huis. (She walked home singing.) Hij kwam huilend binnen. (He came in crying.)
• In fixed time phrases: de komende weken (the coming weeks), volgende week (next week), het lopende jaar (the current year) — all present participles of komen, volgen and lopen.

Both can sit in front of a noun as an adjective, but they mean opposite things. The present participle (-d) is active — the noun does the action. The past participle is passive or finished — the action has been done to the noun.

• kokend water (boiling water — the water is boiling) vs gekookt water (boiled water — someone has boiled it).
• de vallende bladeren (the falling leaves) vs de gevallen bladeren (the fallen leaves).
• een lachend kind (a laughing child) vs een verwend kind (a spoiled child — from verwennen, to spoil).