"She knew her son to have learned German."
"She knew her son had learned German."
"She knew that her son had learned German."
Last edited by ostap77; 14-Oct-2010 at 13:46.
My feeling is that we can use the present or perfect infinitive of BE ofter know + person, but not after other verbs. Thus the first two senetnces below are acceptable, the second too not.
1. I know him to be honest and sincere.
2. I know him to have been brave.
3. I know him to learn German.
4. I know him to have learnt German.
As I am re-reading those sentences, I am finding the second strange. I am now more inclining towards:
2a. I have known him to be brave.
I am going off to hunt through my grammars. I shall return to this thread to see what others think.