In my story, giants are about 14 feet tall with long, almost elephant-like legs and feet. The giants' language is not verbal, but is instead spoken through the stomping of the feet and individual toes tapping. A giant's feet are very sensitive to vibrations, meaning they can feel even they can clearly understand what another giant is saying. My giants are able to sing, more specifically throat sing, but the songs themselves have no actual lyrics they can understand. Because of this they aren't really able to socialise, or even talk with most other species. So why would my giants be unable to spoken language, or if you want, why would they choose to not have a spoken language?
Note: My giants are capable of understanding other species' languages, but they don't really understand most words in these 'foreign' languages