Future: Regular Verbs: 'ER' Verbs
Spanish: Cambridge International GCSE, topic 10.1.2
ER Verbs in the Future Tense
AR, ER and IR Verbs have the same set of endings in the Future Tense. To form the future tense with ER verbs, do not remove the infinitive ending and add the future endings. Here is the example with 'comer':

Comeré - I will eat

Comerás - you will eat (singular)

Comerá - he/she will eat / you will eat (formal)

Comeremos - we will eat

Comeréis - you will eat (plural)

Comerán - they will eat / you will eat (formal plural)
Test yourself on Future: Regular Verbs: 'ER' Verbs
'Llover' is regular in the future tense. How do you say 'it will rain' in Spanish?
'Correr' is a regular verb in the future tense. How do you say 'I will run' in Spanish?