Pensaré, gritará, morirás, ...

— or —

Voy a pensar, va a gritar, vas a morir, ...

There are two ways to comminicate future events in Spanish. In the first one, add an ending to the unchanged infinitive form of the verb. These same endings are used for all three types of verbs (-AR, -ER and -IR), which makes learning them easier:

-é
-ás
-á
-emos
-án

Pensaré: I will think
Pensarás: 'you will think
Pensará: it will think
Pensaremos: we will think
Pensarán: they will think

Iré: I will go
Irás: you will go
Irá: she will go
Iremos: we will go
Irán: y'all will go

The alternate way to describe the future is to use the present tense of "ir," followed by the infinitive of the action verb.

Voy a saber: I am going to know
Vas a mentir: You are going to lie
Va a cazar: He/she is going to hunt
Vamos a contar: We are going to count
Van a poner: They are going to put