it +be动词+adj.形容词+for+sb.+to+do+sth.
例如:
it is good for you to eat an apple everyday.
It +Be+Adj形容词+ for sb to do sth
It's hard for you to find a good job at the moment.
动词:
It cleans the blenchs of the pool.
助动词:
It doesn't work well.
第三人称单数:
It is/was a dog.
动词或助动词
It is difficult for a foreign to learn Chinese.
+be动词+形容词