定语从句：
Our teacher who had teached us is ill.
"who had teached us"是作为“our teacher”的定语从句,如果抛开它,句子也能成立,our teacher is ill.意思也是完整,明确的.
同位语语：
Our teacher advise us that we shoud take care of ourselves in the winter.
"we should take care of ourselves in the winter"是advise的同谓语,如果排开他意思就不完整了,“Our teacher advise us”语义上就是有残缺的,因此它后面的内容为“advise 建议”的内容.