Vixen
Penultimate Amazing
The onus is on the person making the claim. If you want to prove he's a fraud and knows no language at all let alone English the onus is on you to prove it. Digging up a video of an angry outraged YouTuber or a wiki extract citing some guy strongly opposed to disabled people being assisted in expressing themselves is not proof Woody is a con merchant.Quite.
If he knew a language which his mother does not, that would be much more persuasive than being told, by his mother, that he knows four languages.
Or, as mentioned earlier on, if he could describe, via his mother, anything which she does not already know (such as the object in a picture he has seen but she has not) that would be compelling.