Irregular first person in the present tense
Caber – to fit quepo
Caer – to fall caigo
Dar – togive doy
Estar – to be estoy
Hacer – to do/make hago
Poner – to put pongo
Saber – to know sé
Salir – to leave salgo
Traer – to bring traigo
Valer – to be worth valgo
Ver – to see veo
Irregular compounds in the yo present tense
Other Spanish verbs have some of the words above in that word, for instance proponer – to propose has poner in it and as a result has a similar irregular yo present tense form.
Poner verbs: Componer – to compose compongo
Disponer – to arrange dispongo
Proponer – to propose propongo
Reponer – to replace repongo
Suponer – to suppose supongo
Tener: Contener – to contain contengo
Detener – to detain detengo
Mantener – to maintain mantengo
Obtener – to obtain obtengo
Retener – to retain retengo
Sostener – to sustain sostengo
Traer: Distraer(se) – to distract distraigo
Hacer: Deshacer – to undo deshago
Rehacer – to remake rehago
-cir and -cer verbs -> zco
Some verbs that end in cir and cer when in the yo present tense form change to -zco instead of –co
Er verbs: Agradecer – to be thankful/grateful agradezco
Aparecer – to appear aparezco
Complacer – to please complazco
Crecer – to grow crezco
Establecer – to establish establezco
Merecer – to deserve merezco
Ofrecer – to offer ofrezco
Padecer – to suffer padezco
Permanecer – to remain permanezco
Pertenecer – to belong pertenezco
Reconocer – to recognize reconozco
Ir verbs: Traducir – to translate traduzco
Conducir – to drive conduzco
Producir – to produce produzco
cer/cir -> -zo
Some verbs have a cer/cir ending but do not have the –zco ending, instead they have a –zo ending:
Covencer – to convince covenzo
Ejercer – to practice (a profession) ejerzo
Vencer – to overcome venzo
-ger/-gir -> jo
Some verbs have a ger/gir ending but in the yo present tense form are –jo, this is to keep the soft g sound of the verb.
Er: Coger – to catch cojo
Encoger – to shrink encojo
Proteger – to protect protejo
Recoger – to pick up recojo
Escoger – to chose escojo
Ir: Exigir – to demand exijo
Dirigir – to direct dirijo
Fingir – to pretend finjo