Center?

[Paolo18]

I am Italian and therefore I think the it. word "centro" in English should be written this way: "centre" (UK)
as from etymology (centrum), rater than "center" (US). So, I wonder why do not Americans write, in the same way, "centeral" to mean "central"?

[GoesStation]

We put the e before the r to match our pronunciation of the word. There's no vowel sound between the t and the r in "central", so we don't add one.