Grammar: obsessed with, disappointed by

[RachelL]

Hello everybody,

Please could you help me to answer the following grammar confusion? How would I explain the grammar behind verb preposition collocations, such as "is obsessed with", "am disappointed by", etc? I can't find any information as to why main verb is in the past tense (or is it the past particle?)

Thanks ever so much,

Rachel

(Very) new ESL teacher

[Alan]

The -ed forms here are termed participial adjectives. They are, in origin at least, past (a.k.a. passive) participles of verbs, not past tenses.