The two stories are very similar because they have both lost someone.
'On my first sonne' is about a father who has lost his son when he was only 7 years old. 'When we two parted' is about two lovers having an affair and she is being gossiped about.The rhyming scheme in 'On my first sonne' is quite different to the one in 'When we two parted' as in my first sonne he doesn't finish the poem this could show that he is distraught about losing his son. In when we two parted where the rhyming scheme is as it is supposed to be e.g.
a,b,a,b,a,b.There is a quote in my first sonne which says 'Seven years thou wert lent to me' This is saying that God only let him borrow his son for seven years only to be taken back.In when we two parted it is about an affair which turns wrong so the woman starts to be gossiped about in the town .She feels like an outcast as in those times it was bad enough to have sex while you was unmarried, and she has done it while she is unmarried and having an affair.
While in my first sonne the first line tells us that Johnson considered him to be the child of his 'right hand', signifying the importance of the role that the child would have played had he grown older.In line 5 Johnson pours out his grief in the phrase 'O, could I loose all father', wishing that he did not have to take on the role of a father who loves his son so dearly, because it is so painful to mourn a child. However, the poet then goes on to say 'For why / Will man lament the state he should envie?' meaning that it is strange to grieve over death, as death is something to be envied, something to look forward to. He explains this feeling in line 7 when he says that death is an escape from 'worlds, and fleshes rage', an escape from the anger that we encounter throughout our lives. Then in line 8 Johnson says that even if there are no problems in life, death is at least an escape from age, in other words old age.