try on

try on
试穿，试试看
The clerk held out a dress for Martha to try on.
店员拿出一件衣服给玛莎试穿。
Mary tried on the dress and found it was too tight.
玛丽试穿那件衣服，觉得太紧了。
Try on the shoes before you buy them.
买鞋要先穿上试试再买。
May I try on this sweater?
我可以试穿这件毛衣吗？
The clerk held out a dress for Martha to try on.
店员拿出一件衣服给玛莎试穿。
Be careful when you try on the dress it's only pinned.
试穿这件连衣裙要小心--只是用针别住的。

详解：

try on和try out这是一对try+副词组成的词组。
try on:指“试穿（衣服、鞋子）”及“试戴（帽子）”等，其中的on为副词，当宾语是代词时，该宾语要放在on之前；如果宾语是名词，该宾语放在on之前或之后均可。
试穿衣服
try on a coat＝try a coat on
这新帽子是给你的，请试试看。
The new hat is for you．Please try it on.
try out: t指“试验或试用”某种机器、理论或方法，其中的out为副词，当宾语是代词时，try out要分开用。
去年我们大面积试种这种新庄稼。
We tried out this new crop on a large area last year.
我来试试看能否行得通。
I'll try it out and see if it works.

too...to<-->try out