Open, closed, or hyphenated? Clearing up the compound confusion

Compound words are often born with a hyphen. Some evolve into open compounds, others become closed, and the odd one remains hyphenated. And, the same word can be treated every which way depending on the dictionary you check. Furthermore, many compounds add or drop hyphens depending on their function in a sentence. No one can be expected to keep track. Follow these guidelines for how and when to hyphenate compounds.