@abelebron
Regarding what you said about fire magic, we do see May Craven use the work to destroy the collars. i think that this work is extremely forbidden given the taboo around burning witches. Alder says something along the lines of "If we must burn this evil from the earth, then so be it," regarding the witchplague which could be interpreted as her being willing to bring back fire work to deal with it.
This is a GREAT detail! The whole scene is just jam-packed with information, too, thank you for bringing it to my attention.
Tally is the one who first brings up burning the collars to destroy them, not any other sort of destructive Work she may have learned in the military.
Then, May is the one who says "I got this", preempting whatever Tally was going to do to burn the collars. Possibly because she didn't think that Tally had a safe way to destroy them in a controlled way, while May did? As in, what she does next is something she never taught Tally, or perhaps there's an associated cost/burden she was willing to spare Tally from.
Then, according to the irl creator of Mothertongue, May specifically speaks a more archaic "Proto-Méníshè" to carry out the Work.
An Archive of Our Own, a project of the Organization for Transformative Works
She also says very specifically "burn the collars", and not something more wide-ranging like "burn this room/building". Of course, the moment the van pulls away, the building does explode, so. (Or can we actually chalk that up to the command, and assume there were no human casualties?)
This fire doesn't come into existence from nowhere. May has to strike a match first, and so it seems like she uses Mothertongue to directly speak to the flame itself.
There is the fact that May, coming from a culture of Californian conscientious objectors (Tally's own description from 1x1), who never learned any military Canon (but did teach Tally sigil Work), using an older form of Mothertongue to cast the only case of fire Work we see in the show? It definitely seems relevant.
(This might also explain Tally being able to halfway understand Grafton's challenge on the first day of class, putting her further along than High Atlantic Gregory.)
