The English language is filled with words that rhyme but having entirely different spellings. Rhyme time rarely involves a neat beat. Why am I mentioning this? It's enjoyable to get a 'sneak peek' at something, so don't ruin the experience by incorrectly describing it as a 'sneak peak'.
Image courtesy of Shutterstock
It's an understandable mistake to make. Both 'peek' and 'peak' are valid English words, and having typed 'sneak' it's all too easy to repeat the pattern and type 'peak'. That doesn't make 'sneak peak' (or 'sneek peek') acceptable. 'Sneak peek' is the only correct version. You're checking something out in advance, not climbing to the top of it.
Need a trick to remember this? When you look at something, you peek at it. Repeated vowels are what you need in both cases.
Lifehacker's Mind Your Language column offers bossy advice on improving your writing.