Nor is any language “a vague language.” Rather, every language has vague language, just as every language has specific language. Vagueness is a natural phenomenon; not everything in life is certain, specific, accurate, or clear. Since things are sometimes vague, people must be able to use language to express this vagueness. ASL has ways of expressing vagueness; therefore, ASL has vague language in it — just as English and every other language has vague language it it. Any language is too complex to be labeled “a vague language.” Conversely, it is not reasonable to say that any language is “not a vague language” — except insofar as to say there is no such thing as “a vague language.”
Until recently, people thought ASL was “a simple, concrete language incapable of expressing abstract thought.” Research has proved that wrong. My research into vague language (VL) in ASL dignifies ASL by proving that it is capable of expressing vagueness. Can you imagine if it were impossible for an ASL user to express vague or abstract thoughts? If that were the case, ASL would be a limited language. On the contrary, ASL is a healthy, natural language that affords its users the ability to express an infinite range of ideas. That is why I say ASL has vague language, and I support my point with the empirical research I conducted for my master’s thesis “Keeping it Vague: A Study of Vague Language in an American Sign Language Corpus and implications for interpreting between American Sign Language and English.”
I welcome discussion on this topic! Please use the comments section below to respond with whatever thoughts or feelings you have about vague language in ASL and/or other languages.
Daniel Greene 
Comments welcome