Is recibir a stem changer?
An infinitive is the form of a verb that shows no subject or number, such as comprar/ to buy, vender/ to sell, recibir/ to receive. Stems of regular verbs do not change, but stems of irregular verbs sometimes do change. via
What is the present participle for vivir?
The present progressive in Spanish is formed with the present indicative conjugation of the verb estar followed by the present participle (gerundio in Spanish). The gerund refers to the -ing form of the verb. To form the gerund, all -ir verbs take on the ending -iendo, in this case, vivir becomes viviendo. via