Final answer:
The correct form of the verb comer (to eat) that agrees with the subject ellos is comen.
Step-by-step explanation:
The correct form of the verb comer (to eat) that agrees with the subject ellos is comen. In Spanish, the verb form must match the subject in both person and number. 'Ellos' is the third person plural, so the correct form is 'comen'.
Learn more about verb conjugation in Spanish