The simplest formulation is the claim that expressions of the form ‘S is true’ mean the same as expressions of the form S. Some philosophers dislike the idea of sameness of meaning, and if this is disallowed, then the claim is that the two forms are equivalent in any sense of equivalence that matters. That is, it makes no difference whether people say ‘Dogs bark’ is true, or whether they say, dogs bark. In the former representation of what they say the sentence ‘Dogs bark’ is mentioned, but in the latter it appears to be used, so the claim that the two are equivalent needs careful formulation and defence. On the face of it someone might know that ‘Dogs bark’ is true without knowing what it means (for instance, if he finds it in a list of acknowledged truths, although he does not understand English), and this is different from knowing that dogs bark. Disquotational theories are usually presented as versions of the redundancy theory of truth. See also formal/material mode of speech.