To discuss is to talk about something with someone.

• We will discuss this matter when we meet next week.

Discuss something with someone

• I must discuss this problem with my landlady.

Discuss can be followed by a question word like how or why.

• We are meeting to discuss how to deal with this new issue.
• When we meet next week, we will discuss why we should allow this.

Discuss can also be followed by a noun clause introduced by the conjunction whether.

• We have to discuss whether we should continue working on that project.

Common word combinations with discuss.

Discuss is directly followed by an object. Here are some nouns commonly used with discuss.

Discuss an issue / matter / subject / topic / plan / proposal / question

Grammar

Discuss is one of those verbs that are never used with a preposition. It is simply followed by a direct object.

• When we met last week, we discussed his pet projects. (NOT When we met last week, we discussed about his pet projects.)
• I like to discuss music and movies with my friends. (NOT I like to discuss about music and movies with my friends.)
• I would like to discuss the advantages and disadvantages of young children using the internet.

The noun discussion is followed by the preposition about.

• We had a discussion about movies.

Or you can say:

• We talked about movies.