I speak English as a second language 里面as是起什么作用的修饰什么的

I speak English as a second language 里面as是起什么作用的修饰什么的 I speak English as（）second language most people speak English as a second language介词为什么用as? learn English as ( a ) second language. Most people speak English as a second language.句中为什么用a,而不用th speak English as their first,second or a foreign language th He thought most people speak English as a second language.中的 with English as a second language是指什么样的国家? English _____(use)as a second language in some countries why english is very important as a second language? How mang people learn English as a second language 请问English as a Second Language是什么意思呢?怎么读?