How can I teach new spells to a follower?

Solution 1:

I have done a lot of testing on this and have yet to find a way for a companion to actually learn a spell. If you give them staves that have spells on them they will spam them. As long as they are not conjuration spells. I used Lydia and when given conjuration staves she will revert to her bow and will not even equip the stave that summons. I am also unable to unequip her bow and arrows. They seem to be "Basic" companion items they always have.

So in short: No they cannot learn spells.

Although: If your companion is a spell caster they will cast the spells they already had but will not learn more.

Solution 2:

You can teach your followers new spells via console commands on the PC version. To do so, you will first need a hexcode for the spell you want to add.

To find out the hexcode, open up the console (by hitting the ~ key) and type in:

help "SPELL NAME" 4

Where SPELL NAME is the name of the spell you want your follower to have. For example, if you want your follower to be able to summon a Frost Atronach, type:

help "conjure frost atronach" 4

This will return several hexcode values. The ones you're looking for start with the 4-letter string "SPEL".

In this specific case, there are 3 spells for Conjure Frost Atronach. I'm pretty sure (but not 100% sure) that the spells are listed from least to most powerful. The first hexcode listed for Conjure Frost Atronach is 000204C4.

To give your follower this spell, target the follower with your mouse cursor while the console is open and type:

addspell 000204C4

And voila, your follower now has the ability to summon a Frost Atronach.

Solution 3:

If playing on the PC, installing the mod, Ultimate Follower Overhaul, will allow you to get followers to learn new spells.

One of its features is:

[To] make a follower use a spell tome from inventory to learn a spell

It also allows followers to "forget" their learned spells.