onto
介词 prep.
1.到...之上;向...之上
The cat jumped onto the chair.
猫跳到椅子上。
The boy climbed onto the roof top.
男孩爬到屋顶上。
2.【口】对...熟悉,对...了解
It didn't take him long to get onto his new job.
他很快就熟悉了新工作。
The police are onto the robber's plans
警方对盗贼的计划了若指掌。
onto-
=ont-
upon
介词 prep.
1.在...之上,在...上面
He laid a hand upon my shoulder.
他把一只手放在我肩上。
2.在...后立即
3.根据;依靠
We acted upon his instructions.
我们根据他的指示办事。
4.接近
5.对着,向
6.(走)上...,(爬)上...
He climbed upon his horse.
他爬上马背。
7.在做...之中
8.关于