I have a question about the case when i have to use the word would. Today I saw your comment that I should have added the word in front of consider. Could you give some more elaborate explanations?

Yes, it's a little bit complicated. I think I can explaing it better in class, but basically, because you are telling me what your coworker said(past tense), and he was saying what he will do(which is consider what you asked)  we will use the past tense of "will" which is "would." So he said to you, "I will consider it," then you told e about the conversation which happened in the past, so "He said he would consider it." 

Hope this helps. I'll explain better in class :)