I am studying English language. I have read a rule that there must be used article 'a/an' before profession. This rule is written, for example, this blog post says, "You'll see that English puts an indefinite article in front of a profession but German doesn’t." But I think that this rule is not working if I mention profession second, third time. For example I think I could say something next:
Our teacher of english language said that we need to use articles. The teacher
said talked about differences between two types of articles.
The question is: is it okay to use 'the' in second mention. And second question: may I say article 'a' before teacher in the second sentence from example.