preterite (future)Verbs ending:-car, -gar-zar

* Verbs ending in -GAR. The g changes to gu before e: yo llegué (I arrived)

https://www.elconjugador.com/conjugacion/verbo/llegar.html 

* Verbs ending in -CAR. The c changes to qu before e: yo practiqué ( I practiced)

https://www.elconjugador.com/conjugacion/verbo/practicar.html 

*Verbs ending in -ZAR. The z changes to c before e: yo empecé ( I began) 

https://www.elconjugador.com/conjugacion/verbo/empezar.html