曾经我有一个爱，他是一个气体，不久很快就变成讨厌鬼。

Once I had a love and it was a gas, soon turned out to be a pain in the ass.

youdao

座位很快就占满了，不久就只剩下站立的地方了。

The place quickly fills up so it's soon standing room only.

《柯林斯英汉双解大词典》

克林顿果然学得很快，不久就着手解决降低预算的重大问题。

Clinton proved to be a quick learner and soon settled into serious struggles over cutting the budget.

《柯林斯英汉双解大词典》