Two verbs (be and go) that contain suppletive forms
The Old English verb for 'be,' like its Modern English counterpart, combined forms of what were originally four different verbs (seen in the present-day forms be, am, are, was). Paradigms that thus combine historically unrelated forms are called suppletive.
Another suppletive verb is gan 'go,' whose preterit eode was doubtless from the same Indo-European root as the Latin verb eo 'go.' Modern English has lost the eode preterit but has found a new suppletive form for go in went, the irregular preterit of wend (compare send-sent).
|be / am / is / are||was / were||been|
|go / goes||went||gone|
To find the correct form, you can use an online database of the irregular verbs.
For example: irregular verb BE