1. We had great fun playing in the water.
2. I found a small boy crying in the corner.
3. I helped him find his father.
4. That made me feel very happy.
请注意playing,crying和find, feel,为什么前者要加ing, 后者用原型,不要说公式(如help sb do sth),最好解释清楚。
这些都是过去时,与时态问题无关,WINNIE1984WLL 说的似乎有点道理,但是有些听不懂
参考资料:我英语是全年级第一的,肯定没错,选我!^_^