I'm a big believer in looking things up. People who are baffled by finer points of grammar and usage are often amazed to learn how many mysteries can be solved simply by opening a dictionary.
I'm not just talking about spellings and definitions. If you don't know whether you've drank or drunk your coffee, whether your picture is hanged or hung, or whether you want to stay for a while or stay for awhile, your answers can all be found in a dictionary. (For folks keeping score at home, the abridged answers are: you've drunk your coffee, your picture is hung and you stay for a while.)
But occasionally I come across a language issue on which the dictionary actually adds to the confusion. Specifically, I'm talking about "compliment" and "complement."