Do the French have any verbs, whose perfect (passé) tense forms base on the lexical root, that differs from the lexical root of the infinitive form (by analogy with the Latin verb fero > tuli)?
Aller is the obvious example, since it alternates between three stems, with a different one in the present and in the perfect (I also include examples in the compound past which replaced the perfect more or less completely):
Je vais ↔ j'allai
Je vais ↔ je suis allé
Être maintains the Latin stem change between sum and fuī:
Je suis ↔ je fus
Je suis ↔ j'ai été
And avoir's stem has attrited to nothing in the past participle and the perfect (it is preserved in writing as ⟨e⟩ but not pronounced), creating another alternation:
J'ai ↔ j'eus
J'ai ↔ j'ai eu
That approach has not been adopted in the conjugation of the verb in French ; the lexical root perdures throughout the whole conjugation with in some cases a change in a vowel or a consonant but not on the basis of an opposition between types of tenses ;
- faire : je fais (présent), je ferai (futur)
- peindre : je peins (présent), je peigne (subjonctif présent)
There is another particularity of the French verb, although it's true for only a few verbs, and that's the occurrence of missing forms, as in this case (paitre).