Present participles are easily recognized by the addition of a –d to the infinitive form of the verb. Thus schwimmend = swimming, laufend = running, etc.
German uses present participles primarily as adjectives and adverbs, not as verbs. Remember that English present tense, “he is running,” “she is swimming” etc., is expressed in German with the present tense: er läuft, sie schwimmt.
Examples of present participles as adjectives and adverbs:
das spielende Kind
the playing child [or, more naturally in English:] the child who is playing
der singende Vogel
the singing bird
Das Spiel ging enttäuschend aus.
The game ended disappointingly.
Der Hund stand bellend am Fenster.
The dog stood at the window barking.