Interesting topic! I was taught that if I was going to use, 'however' in middle of a sentence it should be after a semi-colon. However, that could be because our grammar was so bad, our grade 6 teacher started us from the beginning. She followed the KISS method for us: keep it simple stupid. Anyways, I mostly use, 'however' in the beginning of a sentence or in the middle with a semi colon. How wrong or right is that? Something like, "I am Canadian; however, I live in Mexico".