once后面加现在完成时什么意思异形4里面一句话，某教授谈到异形时说它Thepotential,unbelievable.Oncewe'vetamedhim，异形潜力无穷，不可思议，我们还可以驯服它。Once后加现在完成时怎么理

Question

once 后面加现在完成时什么意思
异形4里面一句话，某教授谈到异形时说它 The potential, unbelievable. Once we've tamed him ，异形潜力无穷，不可思议，我们还可以驯服它。Once 后加现在完成时怎么理解？

Answer 1

once后既可以使用一般现在时，也可以使用现在完成时。
例如：
Once you start,you will never give up.一旦你开始了,你就不要放弃.
Once you begin to read it,you will like it.一旦你开始读,你就会喜欢它.
Physics is easy to learn once you understand the rules.一旦你理解了规则,物理就不难学了.
Once you have learned how to swim,you will never forget it.
Once you have been working from home for a while,you might feel a bit lonely.