如果想和对方说 微笑.是smile还是 smiling.这个用名词还是动词合适

问题不大,可是内容很深
smile 做为动词,我想你知道这个用法
i smile,不及物动词,最常见
smile 做为名词,和动名词的smiling 还有现在分词（形容词性）的区别,要重点讲
The smile froze on her face,做为名词
smiling is better than crying 做为动名词
做为现在分词,非谓语的用法：
when i enter the room,smiling=when i enter the room,i was smiling