Spelling-change verbs: -cer / -cir

Verbs ending in a vowel + -cer or -cir insert a z before the c in the yo present form: conocer → conozco, conducir → conduzco. This is the only affected indicative form — tú, él, nosotros etc. are regular.

No — hacer ends in -cer but is preceded by a consonant (h), so it follows different rules. Hacer is a go-verb: hago. The vowel + -cer rule applies to verbs like conocer, ofrecer, parecer, and nacer, where the -cer is preceded by a vowel.

Yes — conducir and traducir fall into this group (-cir verbs). Their yo present forms are conduzco and traduzco respectively. They also have an irregular preterite stem (conduj-, traduj-) which places them in the broader irregular category.