Los verbos con la forma Yo irregular

Remember that regular present tense -Ar, -Er  and -Ir  verbs are conjugated by removing the -ar, -er,or -ir infinitive endings and adding the correct endings for each conjugation:

But some verbs conjugate differently in the Yo form.  They don't simply add "o".
Dar  and Ver  are among the irregular Yo form verbs.  Because they are three-letters long,  we have to add a bit more back to the Yo form:

• We can't have *Vo, so we need to add the "e"  back.

• Some irregular "Yo" verbs like Poner, Salir, Oír  and Hacer  have a "-go"  ending for the "yo"  form
• Others like Dar, Estar, Ser and Ir have a "y" ending for the "yo" form
• And others like Conocer, Traducir  and Conducir have a "-zco"  ending for the "yo" form

Some verbs like Oír not only have an irregular Yo form but also have additional changes.  The yo form is irregular, but so are the others.  The "i"  has to change to a "y" inbetween the vowels "o"  and "e".  The Spanish "i" cannot handle being between two strong vowels (*oie).  The "i" is too weak to be heard between the "o" and the "e"; so it becomes a stronger "y".  Notice the Nosotros  form only has two vowels (one of which is accented) so the "i" stays an "i".

*[exceptions] Saber (click to see more about Saber) has an irregular "yo" form, sé , but is regular in all the other forms of conjugation. Haber has an irregular "yo" form, he , but is regular in all the other forms of conjugation.