Please help. I am helping my Spanish friend with her English and we have a, what I hope is a small problem. Are there any rules to determine the endings of the following words and when to use them.
Know - knowledge as in 'I know English' and ' I have knowledge of English'.
Tough - toughest as in 'He is tough' and 'The toughest of men'.
Suffer - suffering as in 'I had to suffer it' and 'To end the suffering'.
It's so long since I left school I really don't know how to explain some of them.
In brief - when do you use the different endings. Is there a rule to say when and which to use? Hope somebody can help.
Know is a verb 'to know', knowledge is a noun.
Tough is an adjective, toughest is its superlative.
Suffer is a verb, 'to suffer', suffering can be an adjective, the present continuous form of suffer etc. depending on context.