Hi, I am not a native speaker and try to memorize as much vocabulary as I can.

My problem is I know there are tons of English words out there, but how can I only memorize the useful and common words.

For example, when I was studying in a language school, I wrote the word " eleemosynary" on the board, which I read in a novel written by Stephen King called The bizarre Of Bad Dream, only to find my teacher, a 45 years old Canadian, had never seen that word in his life.

So I am wondering where I can memorize those vocabulary native speakers memorize and those that common and useful ?

Though my intuition tells me that because SAT vocabulary is for students aiming to study in university, the words list would be very common and useful, I am not sure in that I wasn't being reared in English environment.

If you guys are willing help me, I would so appreciate that!