H. P. Grice was fascinated with Hintikka's approach to the "Cogito". He is a Finnish philosopher (Hintikka).
J. M. Geary provides nine variants to the Cogito.
They are all in English.
Descartes's mother tongue was French, but he preferred his Father tongue -- and so he provided both mother tongue and Father tongue (Latin) versions of it.
Geary sticks to English:
(1) I think ...in a manner of speaking.
(2) I think I am therefore I think.
(3) I think I think I am.
(4) I think I am, therefore I think I am.
(5) I think I am not therefore I am.
(6) I am therefore I think I am.
(7) I think not, therefore...
(8) I am I before I am knowing I think.
(9) I am thinking that I am thinking that I think.
Jaakko Hintikka offers a nonsyllogistic interpretation of cogito ergo sum.
He claims that one simply cannot doubt the proposition "I exist".
To be mistaken about the proposition would mean something impossible: I do not exist, but I am still wrong.
Grice: "The Cogito does not seem especially qualified [as an example of certainty] since the certainty of my existence seems to depend NOT notably on clear and distinct perception [Descartes's criteria of both objective and subjective certainty, x is certain, I am certain] but rather on (i) the fact that it is immune to the hypothesis of the malignant demon and (ii) the fact that "I exist" is one of a special class of propositions (statements) (cf. "I am awake") whose truth is required in order that their expression should count as the making of an assertion. An utterance of "I exist" is true or not a statement-making utterance at all."
In using "I am awake", Grice may be disimplicating his colleague (occasional) at Cornell, Malcolm, whose favourite statement-making utterance was: "I am dreaming", or on occasion, "I am asleep" (versus "You are asleep", or "He [Black?] is asleep."
Abraham, W.E. "Disentangling the Cogito", Mind 83.
Boufoy-Bastick, Z. Introducing 'Applicable Knowledge' as a Challenge to the Attainment of Absolute Knowledge , Sophia Journal of Philosophy, VIII
Descartes, R. (translated by John Cottingham), Meditations on First Philosophy, in The Philosophical Writings of Descartes vol. II (edited Cottingham, Stoothoff, and Murdoch; Cambridge University Press)
Grice, H. P. Studies in the Way of Words: Part II: Explorations in semantics and metaphysics.
Hatfield, G. Routledge Philosophy Guidebook to Descartes and the Meditations (Routledge)
Hintikka, Jaako. The Cogito.
Kierkegaard, S. Concluding Unscientific Postscript (Princeton)
Kierkegaard, S. Philosophical Fragments (Princeton)
Williams, B. A. O. Descartes, The Project of Pure Enquiry (Penguin)
Baird, Forrest E. and Walter Kaufmann. From Plato to Derrida. Upper Saddle River, New Jersey: Pearson Prentice Hall.
Macmurray, John. "The Self as Agent".