How does phenol show tautomerism?

I read that atleast one alpha carbon has to be sp3 wrt the functional group (and has to have atleast 1 alpha Hydrogen atom) for it to show tautomerism.


I am able to see that in the keto isomers of phenol.


However looking at phenol (enol isomer), how does one predict it can show tautomerism?


I'm wondering if some method can be used to identify that.




All [enols](https://en.wikipedia.org/wiki/Enol) exhibit tautomerism, at least to some extent, but not all ketones can tautomerise.


Conditions for showing tautomerism (for ketones) are listed below:


1. Presence of at least one alpha H at the $\ce{sp^3}$ hybridized alpha C (i.e. C just next to the carbonyl carbon)
2. In case of alpha-beta unsaturated ketones/aldehydes at least one alpha H
should be present at the gamma carbon (i.e. third to the carbonyl C).


Also keep in mind some basic rules such as [Bredt's Rule](https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Book%3A_Logic_of_Organic_Synthesis_(Rao)/02%3A_Rules_and_Guidelines_Governing_Organic_Synthesis).


For better understanding refer to [this](https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Organic_Chemistry_(LibreTexts)/22%3A_Carbonyl_Alpha-Substitution_Reactions/22.01%3A_Keto-Enol_Tautomerism).


 1