1 他一回来就买了房子住了进去
no sooner...than..."一...就..."和hardly …when 意思一样 如：I had no sooner reached home than it began to rain.我一到家天就下起雨来
Hardly had she had supper when she went out.“她一吃完晚饭就出去了.”
两个动作是同时发生的，但是还是有一点逻辑上的先后，比如他一定是先回到了英国再买的房子，我一定是到家了，天才下的雨。
希望我的理解能对你有帮助。^_^