let's (里面是ing形式还是原形?) TO SB about STH?

let's sb to do sth还是doing sth let's 是加动词ing 还是加动词原形? 关于let句型是let sb do sth还是let sb to do sth let sb.do sth.该否定句是let sb.not do sth.还是let sb.not to do sth let sb do sth还是let sb to do sth let's 后面加动词原形还是v＋ing形式啊 是talk to sb about sth还是talk with sb about sth,二者有什么区别? it's no good 是加动词ing形式还是加to do sth. let sb do sth 中 是指动词原形吗? Let后面应该加ing形式还是动词原形？ let后面加动词ing形式还是原形 是complain to sb for sth还是complain to sb about sth?