Menary's argument appears to be, in essence, that a thought S is just an unvocalized sentence S and thereby has the meaning of S when S is expressed - vocalized, written, printed, signed, etc. Ken disputes that the thought S is literally the sentence S, but is instead a representation of S (in something he calls "mentalese"). Specifically, Ken says:
Thinking in English is not a matter of sound streams bearing derived content being found in the brain. ... [There is no] token of [a sentence in, say, English] that bears derived content occurring in the brain.