一、population常与定冠词the连用,作主语用时,谓语动词常用第三人称单数形式.
例如: The world's population is increasing faster and faster. 全世界的人口增长得越来越快.
二、当主语是表示人口百分之几时,谓语用复数.
例如：About seventy percent of the population in China are farmers. 中国大约有百分之七十的人口是农民.
三、有时population可用做可数名词,可以和定冠词连用.
例如：China has a population of about 1.3 million.
there is a population of 1.3 million in china.
在表示多歌地区的人口时,population 要用复数.
例如：many parts of world , which one had large populations and produced plenty of crops,have become deserts.
四、在修饰population时,人口多要用large,人口少用small.
五、像这样的词还有：audience,club,family,government,committee,company,crew,crowd,enemy,group,Party,team,policy.
六：hair
当做头发讲时,它是不可数名词,谓语动词用单数.
当做几根头发讲时,为可数名词,谓语动词可以用复数.hairs