Iago has been systematically conning Roderigo out of his money, saying that he is using it to try to get Desdemona to dump Othello and go for Roderigo instead. Iago knows that Desdemona will never do this, and has been simply pocketing the money. Roderigo is starting to catch on, so Iago feeds him the same line about Cassio and Desdemona having an affair and sets Roderigo on to murder Cassio. His objective is to get rid of both of them. Roderigo does stab Cassio, who Iago takes for dead, so Iago kills Roderigo himself.
Roderigo and Iago have several long conversations in which Iago responds to Roderigo many times. The question needs to be more specific.
Iago.
Roderigo.
Iago would get to keep the gifts Roderigo had sent to Desdemona that he had stolen
Why does Iago say that he felt like stabbing Roderigo?
Iago hated Cassio because he was promoted to lieutenant instead of Iago. This was his motive for getting him dismissed, for persuading Othello to hate him, and for trying to kill him. Iago was using Roderigo as a source of money, but Roderigo was beginning to realize that he was Iago's dupe, and was becoming dangerous to Iago--hence he had to be killed.
well i know that this takes place after Othello, the Duke and Brabantio discuss the marrage between Desdemona and Othello, right after everyone in the room had left all except for Roderigo and Iago and In case anyone else didn't know this novel is really a play written by William Shakesphere
During the brawl, Iago kills Roderigo.
Roderigo pays Iago large sums of money to help Roderigo's attempt to woo Desdemona. Iago just pockets the money because not only is Desdemona totally committed to Othello, but could never be interested in a twit like Roderigo.
He killed Roderigo.
So he can keep on cheating him out of his money. As long as Roderigo is prepared to pay Iago to pay court to Desdemona, Iago will keep on pocketing the money and persuading him to pay more. It is only when Roderigo says he will go to Desdemona and demand his cash back that Iago takes action.