OK, nobody asked this one, but I couldn't resist:

aperture

Note that there is only one "a" in "aperture". It is incorrect to write or say, "aperature."

height

Notice that there is no "th" at the end of this word. Resist the temptation to spell "heighth" or to make a "th" sound when saying this word. The "th" isn't there; it's silly to pronounce the word as if it were. I suspect that the origin of this bizarre error is the temptation to say, "length, width and heighth," or perhaps from some origins in Old or Middle English. According to dictionary.com, 90% of a usage panel surveyed disapproved of an extra "th" sound at the end.

lens

The word "lens" is singular. There is no "e" at the end in the singular form. "Len" is not a word in English. The plural of "lens" is "lenses".

noise

This word is frequently spelled incorrectly as, "noice."