They are climb trees这句话哪里不对
问题描述：
They are climb trees这句话哪里不对
答
be+动词ing表示现在正在做，若有be动词，则后面的动词需用现在分词（ing)，即
They are climbing trees. （他们正在爬树）
答
are是be动词，climb是动词，两个动词重复，只有在现在进行时才会用be+doing
答
如果要用一般现在时就直接They climb threes.不用are.但如果想说他们正在爬树就要用现在进行时,They are climbing trees.
答
They are climbing trees