Every time I spell "unnecessary", I struggle to remember whether there are 1 or 2 n's, 1 or 2 c's, and 1 or 2 s's. Anybody have any strategies for remembering how to spell this word?
Here are mnemonics for the spelling of this word based on general English spelling patterns.
The word "unnecessary" is obviously composed of the prefix "un-" combined with the word "necessary". Each of these is spelled with an "n": combined, this makes two "n"s. This is a general pattern: for words prefixed with "un-", the "n" is not dropped, even if it is followed by another "n", e.g. "unnatural," "unnamed", "unnerving".
The word "necessary" is pronounced with two /s/ sounds. It is very rare for an /s/ sound to be represented by a double "cc": normally, that sequence of letters corresponds to the consonant cluster /ks/ (as in "success", "access", "accent", "eccentric") or simply the consonant sound /k/ (as in "accommodate", "succo(u)r", "soccer"). If we ignore words with Italian spellings, the only word spelled with "cc" that is commonly pronounced with no /k/ sound is "flaccid," and that's an irregularity (the regular pronunciation with /ks/ also exists, and some people prefer it).
If you can remember that "necessary" is not spelled irregularly, then you know that it isn't spelled with "cc" because there's no /k/ in the pronunciation, and since you know there's a double consonant in there somewhere, it must be spelled with "ss".
I don't have a mnemonic for unnecessary, but I do have one for necessary:
Never Eat Cucumber, Eat Salmon Sandwiches And Remain Youthful.
There are other similar mnemonics for necessary apparently.