SOLECISM

When my parents' arrival in town is imminent, worries about solecisms move to the forefront of my mind (and possibly, my sister's though she says she doesn't care).

That is not to say that I don't enjoy either noticing or pointing out the solecisms others utter.

DEF:
n.

1. A nonstandard usage or grammatical construction.
2. A violation of etiquette.
3. An impropriety, mistake, or incongruity.

[Latin soloecismus, from Greek soloikismos, from soloikizein, to speak incorrectly, from soloikos, speaking incorrectly, after Soloi (Soli), an Athenian colony in Cilicia where a dialect regarded as substandard was spoken.]
(American Heritage)