substitute

ORIGIN late Middle English (denoting a deputy or delegate):
from Latin substitutus ‘put in place of,’
past participle of substituere, based on statuere ‘set up.’

USAGE Traditionally, the verb substitute is followed by for
and means ‘put (someone or something) in place of another,’ as in :
she substituted the fake vase for the real one.
From the late 17th century substitute has also been used
with with or by to mean ‘replace (something) with something else,’ as in :
she substituted the real vase with the fake one.
This can be confusing,
since the two sentences shown above mean the same thing,
yet the object of the verb and the object of the preposition
have swapped positions.
Despite the potential confusion,
the second, newer use is well established and,
although still disapproved of by traditionalists,
is now generally regarded as part of normal standard English.

subbing..as in teacher..as in replacing..
as in to set up..hummmmmmmm?
it is not an easy task to go into a classroom
where one is expected to be who one is not..
ie:
not the teacher one was planning on stretching with..
ie:
in a yoga class ..
i find i become all wibbly-wobblity
losing every ounce of know-it-all-ness..
this is a good thing..
i embody shoshin
beginner's mind..even as i ask..
whether verbally or non-verbally..
the students to let go of any expectation..
pre-stored know-how..
let's begin again...
set ourselves up for surprize..
to be awed or hoodwinked..
to replace what we know with what we don't know....

in a beginner's mind there are many possiblilities,
in an expert's mind there are few.
shunryu suzuki