Sonnet III belongs to Marriage Sonnets written by Shakespeare. It is organized into 3 quatrains and a final couplet.the speaking voice talk to a young man, this is unusual and very significance because on the contrary sonnets were generally composed for women.In the first quatrain the speaking voice invites the adresser,a young man, to have a children,to understand his beauty"look in thy glass and tell the face thou viewst", and to bless a mother. The s.v.gives a piece of advice to his adresser who is a beautiful and young man.the function of this quatrain is to introduce the argument of the sonnet: the interlocutoe invites the man to have a children .In the second quatrain there are two questions to convince  the young man to marry a woman and to have children so he can guarantee posterity.the function of this quatrain is to persuade the man,he underlines the importance of the postery.In the third quatrain there is a reference to time.  In particular to April that  is  lovely because in spring nature reborns and this is the right period to have children. The speaking voice underlines the importance of time because the problem is that time passes.the function of three quatrain is to inform the adresser that time is so short that he can't loose it. In the final couplet, the speaking voice invites  the young man not to die single and not to make his beauty die with him. last, quatrain the speaking voice says that the age of the man is the better to becomes dad and so, passes on his beauty.In the final rhyming couplet the interlocutor invites again the beautiful man. In this sonnet the reader can understand that Shakespeare likes the young man a lot. He describes him as a beautiful man. He wants to make him understand his beauty and the importance of having children: young's beauty has to continue in the future. But time passes so Shakespeare hopes that the young man takes quickly a decision.