Why is this English pronunciation rule applied inconsistently? [closed]

I pronounce "privatize" as "praiv^taiz" [corrected by editing] instead of "private eyes"(praiv^daiz) [corrected by editing] despite the t being in the unemphasized, second syllable and appearing in between two vowels, and "lantern" with the t plosion, despite an n being in front of the t and a vowel appearing afterward, like "center" which is aptly pronounced "cenner" in accordance with the rule.

The pronunciation rules that I looked up seemed to suggest that "private eyes" and "lan-ern" were the correct pronunciations. But this is not the case among English speakers (or at least that's how I suspect things to be, having attended English speaking schools for a decade).

Why is this "t" rule not applied consistently? Or is my pronunciation wrong? My pronunciation seems to be in line with the dictionary's standard one at least.

Solution 1:

The rules for /t/ being voiced and "flapped"/"tapped" are not very simple.

For /t/ in the middle of a word, the stress level of the following vowel is what’s relevant. In “privatize”, that’s not the vowel in the second syllable, it’s the vowel in the third syllable. This vowel is an unreduced diphthong and so some analyses treat the syllable as having some amount of stress.

Flapping does occur in atomize and automate, where the /t/ is before a reduced and fully unstressed vowel.

Flapping of /nt/ is optional. I don’t know what might make it more common in some words then in others, but it is usually always possible to use voiceless, unflapped t after /n/.

Related:

• Why isn't the T in "relative" flapped?