You can't really hold language to fault because it's capable of referring to, or even describing non-existent entities. Where would human life and imagination be without unicorns, mermaids, or even 'the furthest star' ? Following Kant somewhat, I'm inclined to believe in two basic criteria of 'truthiness'. Correspeondence and coherence. Correspondence is 'a posteriori' and wholly dependent on the evidence of our senses. The other is mathematical or logical coherence and usually ends up indication an equivalence, or even better a tautology. Taken in their pure and extreme forms neither is particularly useful or significant. 'Protocol statements' (as the logical positivists liked to call them) are bare statements of perceived affairs, and are close to meaningless if they are not situated in a collectively recognisable context, or if they are not part for some identifiable programme of observation. Equally, logical statements of equivalence (eg : 2+2=4 - which establishes an equivalence of the terms on each side of the "= sign") don't tend to be too illuminating either. Where most of human discourse, knowledge and deduction take place is between the extremes, and utilising varying admixtures of the two criteria - hence the thorniness of knowledge and truth. Usually we need both prongs of "Humes Fork" (the a prioi and the a posteriori) to have anything understandable, expressible and worth knowing.