The sentence would sound more natural here to say, 'He does know that fact'. When using 'the', it kind of asks for the plural 'facts'. Or to keep it singular, it begs for what fact are we talking about, '... the fact that...'.
The sentence would sound more natural here to say, 'He does know that fact'. When using 'the', it kind of asks for the plural 'facts'. Or to keep it singular, it begs for what fact are we talking about, '... the fact that...'.