Greetings My professor has told me the following, nevertheless she forgot to say when/what these situations are! Would you help me when it is? She said that save for in very few especial situations we can use the preposition by for active voice sentences, otherwise we must use through or via.
In order to make active voice sentences, you can occasionally use the preposition by. But, except for above, always we must use the prepositions through or via.
No, that's not enough information. I asked you to please provide one example of both kinds of sentences.
