Rhizotonic forms are defined as those verbal forms whose accent falls on the radical, that is, on that part in which no change takes place. So, in order to illustrate what we are saying, let us take as an example the verb to jump:
Present tense
I jump
you jump
he jumps
they jump
Subjunctive present
that i jump
that you skip
let him jump
let them jump
We note that in grammatical persons in the singular, as well as in the third plural, such an occurrence manifested itself. Thus, it is stated that for each verb there are only eight rhizotonic forms: me, you, he and they from the present tense of the indicative and I, you, he and they from the present tense of the subjunctive.
The so-called arrhizotonic forms are those in which the tonic accent falls on the endings, and not on the radical. So, let's go back to the examples in question:
we jump
you jump
that we jump
that you jump
We walking
you walk
that we walk
that you walk
By Vânia Duarte
Graduated in Letters
Source: Brazil School - https://brasilescola.uol.com.br/gramatica/formas-rizotonicas-arrizotonicas.htm