Other Patterns of Past Participle Formation

1. A special group within the weak verbs are those whose infinitive ends with -ieren.

These verbs do not add the prefix ge-.

2. Another special group of verbs are the weak verbs that have an inseparable prefix attached to the stem.

You know already that German verbs have two kind of prefixes: separable and inseparable ones.

Weak verbs like besuchen, erzählen, and entdecken or strong verbs like bekommen and gefallen, all starting with inseparable prefixes, omit the prefix ge- of the past participle and only use the endings, -t for a weak verb, -en for a strong one.

3. Weak and strong verbs that start with a separable prefix squeeze the prefix ge- of the past participle between the separable prefix and the stem.

Here are weak and strong verbs with separable prefixes that you know:

Notice that the separable prefix stays with the participle - it does not separate in the perfect as it does in the present.

4. There is a small group of verbs that cannot make up their mind if they are weak or strong.

They change their stem like a strong verb, but use -t as the ending of the past participle like a weak verb. Within the verbs we have had one example is denken. Its quite irregular past participle is gedacht. I am afraid you have to memorize these verbs, too.