1.A huge number of English learners initially(initial) fail to master the English phonetics so that they can't tell varieties of English apart.Those who complain about the difficulties in learning English should clarify the significance(significant) of English sounds and get down to learning(learn) how to pronounce them well.
2.As Chinese, it's not which English you speak but whether you pronounce it well that matters.So, you must be convinced(convince) that you won't let us down as long as you take some unique methods to practise pronouncing.
3.Maybe it's a little difficult to_select(select) a language as your foreign language.Or rather, you have a prejudice for a certain foreign language.Actually, you may find it absurd to hold the belief that learning English is useless.In conclusion (conclude), you can start with conquering English.