Do you eat fish regularly? What type?
No, I don't eat fish regularly. But I like of the sardine.
No, I don't eat fish regularly, but I do like sardines. [Usually, you like (and then the object, in this case sardines). You don't need 'of the'. ] And because sardines is a plural word (many sardines), you make the sardines plural - ie, add 's' at the end.
I hope this helps.
No, I don't eat fish regularly. However, I like sardines.