be diffferent from与different from的区别（详细例子句子中）

be diffferent from与different from的区别（详细例子句子中）
When people use words and expressions different from the "standard language".
为什么不用“be different from”?different应该怎么用?has different from?还有什么时候要加be,什么时候不用加be?
2.This book is written for readers familiar with the German language.
Q:为什么不用“sb be familiar with sth”?什么时候不用加be,怎么用?
3.Q：what to do with后面要加it
以上问题如果可以具体举例那就最好了.