When you agree with a positive sentence you say so am I/so do I/etc .
- ‘I like cats.’ ‘So do I.’
- ‘I’d love to visit Slovenia some day.’ ‘So would I.’
- ‘I have a yellow T-shirt.’ ‘So have I.’
When you agree with a negative sentence you say neither am I/neither do I/etc.
- ‘I’m not very good at driving.’ ‘Neither am I.’
- ‘I haven’t had a beer for a long time.’ ‘Neither have I. Almost two days.’
- ‘He won’t be able to go fishing.’ ‘Neither will I.’
