1. I am for swimming this vacation.
我贊成這次休假去游泳。
還能這樣說：
I agree with the idea to go out for swimming this vacation.
I favor swimming this holiday.
應用解析：
for all 盡管，雖然；
be for it 惹出麻煩；
but for 如果不是，如果沒有；
for sb. to 使某人做某事，應由某人做
2. Come for a swim.
來游泳吧。
還能這樣說：
Would you like to swim?
Do you want to swim?
諺語：
Good things come in small packages.
好事多磨。
3. Swimming in the lake is forbidden.
禁止在湖里游泳。
還能這樣說：
You can't swim in reservoir.
You are not allowed to swim in the lake.
應用解析：
forbid sb. to smoke 禁止某人吸煙；
forbid sb. the house 不準某人進屋；
Parking forbidden! 禁止停車！
4. My father is teaching my sister how to swim.
我的父親正在教妹妹游泳。
還能這樣說：
My sister is learning to swim with my father's guidance.
My father is telling my sister how to swim.
應用解析：
swim over 從……上滑過；
go for a swim 去游泳；
be in the swim 熟悉內情；順應湖流；
sink or swim 不論成敗；無論如何