Prepositions . (e.g. at, about , for, from, to, with , etc) Prepositions in the English language are a matter of common usage, and it is not always easy to see a pattern.
… Even British English and American English sometimes differ on the customary preposition to use with a particular verb. In the case of expressions using verbs such as discuss , enter , marry , lack , resemble and approach , the verb is usually followed by a direct object , rather than by a preposition. So " We discussed about the matter." would be incorrect. The correct form is "We discussed the matter." ... and ' the matter ' is the direct object. In a similar expression, but using the verb 'talk/speak' , a preposition is added. i.e. "We talked/spoke about the matter." (NOT " We spoke the matter .") Of course, it is perfectly possible to 'have a discussion about a matter' but here the word 'discussion' is a noun, not a verb. ------------------------------------------------------------------ For more information about 'discussed' see Related links below. ( Full Answer )