Semantic relations--Gradable Opposites

Dead and alive are complementary opposites. A living thing is either dead or alive. It can't be both (except maybe viruses 濾過性病毒: Are they dead or alive?). Except as a joke, we can't say that an animal is very dead or slightly dead.  

Gradable opposites are different. Wet and dry are a pair of gradable adjectives. A thing can be soaking wet, very wet, or slightly wet; It can also be bone dry, parched, extremely dry or drier.

In American English, delicious is usually not gradable, but tasty is gradable. We don't usually say "very delicious" (Chinese English: if you do a COCA search for "very delicious," you will find that there are very few examples [probably foreigner English], but "very tasty" is quite common). That's why we don't say "Is it delicious?" (this sounds rather strange to English speakers' ears), but it's OK to say "Is it tasty?" Very tasty, extremely tasty, not so tasty, and tasteless are also OK.

Mmmmm...Lollipop, Shopping Diva, Flickr, I-NC-ND, 77372444_b4035d2e7a.jpg

Mmmmm, this lollipop is so tasty (NOT: so delicious)