They started as same word, but their meanings have drifted apart over time.
Comedian ISMO on the complexities of the word 'tip'
'Poets laureate'? 'Court-martials'? The curious history of postpositive adjectives in English.
How the irregular 'snuck' sneaked into the dictionary
The most common vowel sound in English causes many spelling problems.
A simple way to keep them apart. (Most of the time.)