Before we move on to the conjugation of the [simple past](#/lesson/Verbs.Re10), we have to stop for a moment and look at an important phenomenon in the Dutch language.
The Dutch distinguish between d and t verbs.
We speak of a t-verb when the crude stem (not the 'final' stem!) of a verb ends in the consonants t, h, f, c, k, s or p. All other verbs, i.e. verbs that do not end in any of these consonants, are considered d-verbs.
't Kofschip or pocketfish
It is probably quite difficult to remember these letters separately. To remember them, the Dutch use the words 't kofschip ('the koff boat') or 't fokschaap ('the breeding sheep'), which both contain all of the t-verb consonants. The only consonant that is missing is the letter 'x'. This is not such a problem as there are only very few verb stems that end in -x. A common x-verb is _faxen_ (to fax). For those of you who find it hard to remember 't kofschip or 't fokschaap, I invented a new fish: The "pocket fish". This may be easier to remember for English speakers. Perhaps you will find a better one yourself.
v and z verbs
Remember, that you have to look at the last letter of the _crude_ stem to determine whether a verb is a t or a d-verb. The v and z infinitives can be quite misleading:
Infinitive | Crude stem | Stem | Last letter crude stem | In pocket fish? | d- or t-verb?
zweven
(to float) | zwev | zweef | v | no | d verb
verven
(to paint) | verv | verf | v | no | d verb
lozen
(to dump) | loz | loos | z | no | d verb
razen
(to rage) | raz | raas | z | no | d verb
Even though the stem ends in f or s (both part of pocket fish), the verbs are d verbs, as their crude stems end in v and z respectively.