Are all of these correct? <br/><br/>1. John can't sing nor can I. <br/>2. John can't sing, nor can I. <br/>3. John can't sing; nor can I. <br/><br/><br/>4. John can't sing neither can I. <br/>5. John can't sing, neither can I. <br/>6. John can't sing; neither can I. <br/><br/>Thanks a lot.