how do you spell it?和how can spell it 的区别 ）

how do you spell it是：它怎么拼写.比如人家问你名字,问how do you spell it,答：P－E－T－E－R,Peter
how can spell it ：怎么才能拼写它.比如人家问怎么才能把单词拼写好how can you spell the words well?