Could anybody give me a help please

1) In both contexts the emphasis is on the object. The individual is "the man" because of a random reason; usually becuase they've done something significant or positive: "nice job, you're the man!"

2) "There comes a time" is usually a proverbial preface; "There comes a time when..." usually begins a sentence where what follows is a proverb.

That is only one use of the phrase. Another would be when a person is describing a milestone, stage of life, or when something is "supposed" to happen.

"There comes a time, when a teenager has to think about what he is going to do in the future"

"There comes a time, when I cannot ignore the mess in my closet. I must straighten it out, today".

"There comes a time, when a person looks in the mirror, and realizes that he is not young any more."

thank you all very much