Rocking third-person singular
The pronunciation of <-s> can be /z/ or /s/, but <-es> is always pronounced as /ɪz/.
You may need to as -s or -es to the infinitive form.
Verbs used to be little bit more complicated...
English verbs have evolved drastically since Old English times. In Old English, verb conjugations were more inflected, with endings that indicated person, number, and tense. In the course of English history, inflections started being less popular:
Old English (c. 450-1150):
First Person Singular: "ic lufie" (I love)
Second Person Singular: "þu lufast" (You love)
Third Person Singular: "he/she/it lufað" (He/she/it loves)
Early Modern English (c. 1500-1700):
First Person Singular: "I love"
Second Person Singular: "Thou lovest" (You love)
Third Person Singular: "He/she/it loveth" (He/she/it loves)
Thou stopped being used as a second-person singular pronoun, and inflections for present tense were reduced to <-s> and <-es>. This evolution reflects the broader shift from a highly inflected language like Old English to a more analytic and less inflected language like Modern English, with a greater reliance on auxiliary verbs and word order to convey meaning.
Sometimes I think English verbs are difficult. But then I remember I speak Spanish
López Pérez, S. (2021) Analysis of Subject-Verb Agreement Errors in Third Person SingularVerb Forms by Spanish University Students: A Corpus-Based Study. International Journal of English Linguistics, 11(2), 23- 35. https://doi.org/10.5539/ijel.v11n2p23
Shay, S.(2008) The History of English. A Linguistic Introduction. Wardja Press.