As you know the verb "to replace somebody / something" means "to take the place of somebody / something" or "to supersede somebody / something." I was wondering what form is correct in the following sentences? If both are correct, then what is the meaning of each sentence if I want to paraphrase them?
The previous teacher is a little old and cannot manage to come to the school on a daily basis and now:
1.a. I'm being replaced with him.
1.b. I am replacing with him.
For more clarification, let me bring up another example:
2.a. In modern life, email has been replaced the traditional business letter.
2.b. In modern life, email has replaced the traditional business letter.
Note: as we know, the verb "replace" is a transitive verb. So it cannot be used in a passive tone. These all are confusing me a little! Maybe I am missing something here!