1.valentines can be heart-shaped or can have hearts on 2.most people send valentines ,sentimental heartfelt greeting cards надо составить(дописать) вопросы хвостики .

1. Valentines can be heart-shaped or can have hearts on then, can't they?
2. Most people send valentines, sentimental heartfelt greeting cards, don't they?

1) can't they?
2) don't they?