Hello Charlie , Comparing English with other languages it is quite easier to learn. Chinese students find speaking and pronunciation difficult as well as building correct sentences when having to switch to a different sentence structure than the one they have. Latin language speakers will find English much easier to learn and with some extra effort they would achieve a high level of fluency in a relatively shorter time. What makes English in general easier to learn is that mostly everyone uses it in work , media ,internet,education , reading labels, buying food etc... A constant exposure to the language is indeed the best way to learn it quicker.

the new words and phrase. when i am taught too much one time,i even can not think of one!

some phrasal verbs!

persistent learning

Reading i think. Especially the long and complex sentences.