Which is correct: suffered or suffered.

It's not that simple, but there is only one correct option.

In fact, in the Russian language there were equal verbs to suffer and torment .

However, in the process of unifying spelling in the middle of the last century, the verb to suffer in some sense had to be sacrificed. The authoritative spelling dictionary of the Russian Academy of Sciences, edited by V.V. Lopatin, recognizes as acceptable only its forms of the present tense, which differ in sound from the corresponding variants of the verb to suffer : tormented, tormented, tormented, tormented, tormented, tormented . Nevertheless, in strict literary speech it is preferable to only suffer, suffer, suffer, suffer .

As for the initial form - torment , it does not correspond to the modern spelling norm. You will not find this verb in the academic dictionary mentioned above.

The same applies to the past tense: the only acceptable options are tormented , tormented, tormented . The form tormented is erroneous - after all, in pronunciation it is almost no different from tormented .