Why do you think that He doesn't know him from his schooldays means that he does know him? It would only have that sense if you added something like In fact, he first met him at university.
The meaning of DOES is present tense third-person singular of do; plural of doe.
DOES definition: a plural of doe. See examples of does used in a sentence.
Definition of does verb in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.
Do and does are forms of the verb “to do.” They appear frequently in English sentences, especially when forming questions, negative statements, or emphasizing an idea.
Average household income is lower in the north than the south but this does not affect the performance of its primary schools.
DOES definition: 1. he/she/it form of do 2. he/she/it form of do 3. present simple of do, used with he/she/it. Learn more.
Discover when to use do and does in English grammar. Learn the rules for questions and negatives, see clear examples, and practice with easy exercises to master correct usage.
Recently one of my friends told me that there is distinct difference between 'know of something' and 'know about something' expressions. 'know of' is used when you have personal experience with wha...
"Know about" vs. "know of" - English Language & Usage Stack Exchange
Examples: I know (about) this difficulty/problem. I know (about) Engineering. In the first sentence, it seems to me that "to know" expresses that the speaker experienced the problem/difficulty before while "to know about" only expresses that the speaker has heard or read about it.