"去公园看落叶" 可以用英文表示为 "go to the park to watch the fall leaves"。

"Fall leaves" 是指秋天树叶变色下落的树叶。"Fall" 是英文中秋天的意思，而 "leaves" 是指树叶。

下面是一些英文例句及其中文翻译：

"I love going to the park in the fall to watch the leaves change colors." (我喜欢秋天去公园看树叶变色。)
"The park is especially beautiful in the fall when the leaves are turning red and yellow." (公园在秋天树叶变红变黄时特别美。)
"Let's go for a walk in the park and enjoy the fall leaves." (让我们去公园散步，享受秋天的树叶。)