Present Perfect

The present perfect tense in Dutch consists
of an auxiliary verb, hebben or zijn, and a past participle. In a sentence, the auxiliary (the conjugated verb) takes the second position, and the past participle is placed at the end of the sentence.

Marja heeft (conjugated verb) vorig jaar een nieuw huis gekocht (past participle).

The past participle of a regular verb begins with ge- and ends in -t or -d.
A good way to know and remember when a past participle ends in -t is to use the following trick: SoFT KeTCHuP. If the STEM of a verb ends with one of the consonants in this word, you have to add a -t. All the other verbs with ´soft´ consonants have an ending in -d.

Koken (to cook) has a STEM with a K consonant: Ik heb vorige week pasta gekookt.
Rennen (to run) has a STEM with an N, a soft consonant: Ik ben gisteren naar huis gerend.

Notes:
1. The past participle of a verb with an open
syllable doubles the vowel: maken > gemaakt, spelen > gespeeld.
2. Regular verbs with double consonants in the stem drop one in the past participle: zetten (to put) > heeft gezet, passen (to fit) > heeft gepast.
3. The past participle of an irregular verb begins with ge- and ends in -en, and in many cases the stem vowel changes. The best is to learn these past participle forms by heart.
4. It is more common to use the auxiliary hebben over zijn in the present perfect tense. Because the rules are difficult with a lot of exceptions, it´s best to stick to ´learning by doing´.