Let Mom know how smart you are

So show some respect.
In the obligatory phone call today, casually reveal the history of the word mother.

The word for "mother" in Proto-Indo-European originated in the first recognizable syllable uttered by babies: ma. This syllable was attached to a kinship suffix, -ter, which also turns up in brother, father, and sister. 
The original form, mater-, later evolved into the current words for "