1.have作助动词用，用于完成时态。第三人称单数是has.过去式是had。如，I have finished my homework. He has gone to Beijing.

2.have作行为动词用“有，拥有”,表示所有关系。如，I have a dictionary. He has only one sister. Do you have any brothers? She has a new computer.

3.have行为动词，跟其他词一起组成词组表示多种意思，人称“万能词”。如，They have lunch at school.（吃饭） We were having a meeting at that time.(开会)   类似的词组：have a swim, have fun, have a good time, have sports, have a talk...