4. Some stem changers include (e-ie) (o-ue) (e-i). The stem changes only happen in the boot forms: yo, tú, él, and ellos. Stem Changers
5. Some irregular “yo”s are: –go verbs, (g-j) (c-zc) (ver-veo) (saber-sé). These transformations only happen in the yo form. Irregular "Yo"
6. Saber vs. Conocer Saber means to know a fact or to know how to do something. It is often followed by an infinitive or a subordinate clause. Conocer means to know someone or to be familiar with someone, something, or somewhere. It can only be followed by the a direct object, never by an infinitive or a subordinate clause. Remember that if the direct object is a person, the preposition a must be used.
7. Reflexives Reflexive Verbs are verbs that require a reflexive pronoun when used. They can be identified by the –se suffix appended to the infinitive.