Kofschip

Kofschip is a Dutch grammatical rule used to determine whether a past participle or the genitive plural of a noun should end in -t or -d. The rule is based on the presence of voiceless consonants within the word "kofschip": k, f, s, ch, and p. If the verb or noun stem, when stripped of its infinitive ending, contains one of these consonants, then the past participle or genitive plural will end in -t. Otherwise, it will end in -d.

For example, the verb "lopen" (to walk) has the stem "loop". Since 'p' is in kofschip, the past participle is "gelopen" (walked) and the past tense is "liep". Similarly, the verb "werken" (to work) has the stem "werk". Since 'k' is in kofschip, the past participle is "gewerkt" (worked) and the past tense is "werkte".

Conversely, verbs whose stems do not contain any of the kofschip consonants will form their past participles and past tenses with a -d. For instance, the verb "spelen" (to play) has the stem "speel". Neither 's' nor 'p' are in kofschip in this context. The past participle is "gespeeld" (played) and the past tense is "speelde".

The kofschip rule also applies to the genitive plural of nouns. If the singular noun ends in a voiced consonant, the genitive plural will end in -en. If it ends in a voiceless consonant (as per kofschip), it will end in -s. For example, "kat" (cat) ends in 't', so the genitive plural is "katten". "Hond" (dog) ends in 'd', so the genitive plural is "honden". This rule is primarily for descriptive purposes and is not strictly enforced in modern Dutch.