try to do sth. ：尽力去做某事，不包含是否成功之意。

• First try to do something that is within your scope. 你先试着做一件自己力所能及的事。
• Let’s try to work out this maths problem. 让我们试试解开这道数学题。（强调努力解题这个过程）

try doing sth. ：（用某一办法）试着去故某事。

• Nobody answers the front door. Let’s try knocking the back door.
• You should try using a different approach to solve the problem. 你应该尝试采用不同的方法来解决这个问题。