1：“如果我能飞.我将会在天空飞.如果我不能哭.我将不哭说再见.”
If I could fly,I would fly in the sky.If I couldn't cry,I wouldn't say Good-bye.
2：“如果你能飞,我将不能看得见你（代表不在我身边的意思）.如果你不能哭,我们的生活将是灰黯无光.”
If you could fly,I couldn't keep you in sight.If you couldn't cry,our life would be turning grey without light.
为了帮你达到前后呼应和押韵的目的,同时将你第二句的中文稍做改动,但仍是符合原意的.你看看能与你希望表达的意思吻合么?
◆注：与事实相反的虚拟语气,必须用过去式,前面似乎都没有一人注意到语法上的问题.