I have a bag .itis red 合成一句

Ihavearedbag.
首先要搞清楚连成的句子是陈述句、疑问句（一般疑问句、特除疑问句、选择疑问句、反义疑问句）和否定句，便于大脑快速按照不同的句子排列句子成份。

扩展阅读：nice to meet you ... i have an eraser ... can i see it ... lets go to school ... here you are ... what colour is it ... lets make a puppet ... i have my bag ... guess ...