Why don't "vorbereiten" have "ge-" in participle II?
I have written the sentences with "sich vorberieten" verb. Some were in perfect. Before publishing I checked my sentences with Libre Office Write and was very surprised. I thought "vorgebereitet" is the participle II form of this verb, because vor- is a separated prefix. Then I checked this form of "vorbereiten" with some web-sites, and found "vorbereitet" form. But why? I read this way is only for unseparated prefixes, and there is written that "vorberiten" is not strong verb in dictionary.

Question

Why don't "vorbereiten" have "ge-" in participle II?
I have written the sentences with "sich vorberieten" verb. Some were in perfect. Before publishing I checked my sentences with Libre Office Write and was very surprised. I thought "vorgebereitet" is the participle II form of this verb, because vor- is a separated prefix. Then I checked this form of "vorbereiten" with some web-sites, and found "vorbereitet" form. But  why? I read this way is only for unseparated prefixes, and there is written that "vorberiten" is not strong verb in dictionary.

Answer

Hi,
the reason is because in this example there are actually two prefixes --> vor + be + reiten. When the verb is made of two prefixes, then the participle will not have "ge". This is sort of an exception since in this case vorbereiten is actually a separable verb "Ich bereite mich vor", but the past perfect tense will be kept together.

I hope this helps!
Jaime