Interpersonal theories of communication explain the message which takes place between two people. It focuses on the patterns or relationship which development different people who interact more often. However, there are several theories which illustrate the development of relationship, maintenance and termination of relationship of relationship as well. This paper therefore, covers the two theories which illustrate development of relationship, model of relationship and development and maintenance or ending the relationship. It is also uses various concept of the films to explain the theoretical idea of the film to make it understandable.Evolutionary theory of relationship developmentThe concept of evolutionary theory of development states that all relationships are started with a purpose to reproduce. A stated by Guerrero (192), male and female usually make different contribution during the reproduction stage because they perform different function different reproduction as well. It is because everyone starts relationship with a reason and in most cases, women would want to start relationship with a man who is trustworthy, reliable and committed to relationship because she will need assistance to raise her children (Guerrero 193). In the film “When Harry Met Sally” Sally and Joe broke up because Joes was not ready for marriage while Sally wanted to start a family. It means that Sally did not feel Joe is trustworthy and reliable to secure her future and therefore, she decided to end the relationship. In the film Sally and Harry argues that no relationship can exist without engaging in sexual affair in almost all three occasions they met. It brings out clearly that relationships are for reproduction which explains the evolution theory of relationship development.Attraction theoryAttraction theory illustrates that for any romantic relationship to exist, there must be a person who is interested to initiate contact. Attraction theory explains that there are forces which attract people to relationship and these forces are interpersonal attractiveness, proximity and similarities. For in the film Harry met Sally, Harry and Sally met several times on different occasions and discusses different issues related to relationship. Attraction theory states that relationship begins at a point when people are attracting to each other based on shared interest and therefore, in the film Harry and Sally seems to be having a shared interest to have a family and reproduced. It is noted that “Harry told Sally that she is attractive and beautiful though Sally looked shocked and broken by such word, they ended up meeting again and confess their affection one another and therefore, Hurry and Sally ended up getting married.Models of Relationship developmentMost relationship is developed through shared value and similarities which exist between couples. In a romantic relationship, it is proper to have attraction to each other so that individuals can have a lot to share. Similarities are values people share, vision and other things which bond couples. Therefore, in the film Harry met Sally, have some similarities since both graduated from the same university, shared the same vision in life since both Harry and Sally had plans to start a family. Harry noted that he would want to be a family man at the same time Sally left Joe because she felt Joe was not serious about starting a family and therefore, Harry and Sally have similarities which make their relationship to development despite the fact that both had past relationship, the still ended up loving each other and getting married to have a family.The proximity between harry and Sally also strengthen their relationship hence made them to become couples. In the film, Harry and Sally unexpectedly run into each other in the bookstore, on the flight and they also met in several occasions to discuss their past relationship. This made it possible for them to develop their relationship hence becoming familiar with each other. This made Sally and Harry to start liking each other and therefore, they ended up discussing their personal feelings towards each other, though on the first date, Sally predicted she was not for the topic but ended up expressing her feelings to Harry.Maintenance or ending relationshipRelationships are always terminated when either partner does not see the value of the relationship. It is mostly affected by what and how each partner contributes to the existence of the relationship. It can be ended when there is not shared value and similarities as well. For instance, Sally and Joe ended up their relationship since it was not based on any shared values or similarities. Sally was ready and willing to settle down and start a family while Joe was not committed to long term relations and never wanted to start a family as soon as Sally wanted (Reiner and Nora 2). In relationship the partner should be satisfied and satisfaction can be through sexual and equity and therefore, without either relationship would fail. For instance, Sally and Harry agreed that relationship between male and female cannot exist without sexual intercourse. In the film “Harry met Sally” Sally had sex with Joe, Harry with Amanda his ex-girlfriend to keep their relationship strong and therefore, sexual intercourse and equity are some of the best method which can be used to maintain relationship.In conclusion, the film “When Harry met Sally represents themes of communication theories. The characters explored model of relationship development and theories of relationship development to build the relationship. The relationship between Harry and Sally is a classical example of how interpersonal theories and model determines the existence of relationship in the world of today.Works CitedGuerrero, Laura K. Communication in close Relationship. New York: Pearson, 2014.Reiner, Rob and Ephron Nora. When Harry met Sally . New York, 1989.