They started as same word, but their meanings have drifted apart over time.
These people needed a computer
We're intent on clearing it up
Many of today's grammar rules can be traced to the opinions of one 18th century writer.
You don't have to end all your adverbs in -ly to talk right.
Comedian ISMO on the complexities of the word 'tip'
Some practical guidance, and interesting history, about a common mistake.