How come "informed (past tense)" was used after "keep"? Shouldn't it be "inform"? or is there any word omitted?
Answer from a Native speaker
No, "inform" should not replace "informed" here. "Informed" is used as an adjective for the verb "keep". "Informed" as an adjective refers to having knowledge about a situation. You can think of this phrase as "keep me knowledgeable about what is happening". "Inform" can be a verb or adjective. Ex: My sister informed me that she's getting married. (Informed used as a verb) Ex: The police kept the reporters informed about the robbery. (Informed used as an adjective)