Mistake, putting nothing into English educational foundation? (5)
I believe the answer is:
error
'mistake' is the definition.
('error' can be a synonym of 'mistake')
'nothing into english educational foundation?' is the wordplay.
'nothing' becomes 'o' (looks like zero - 0).
'into' is an insertion indicator.
'english' becomes 'e' (abbreviation).
'educational foundation?' becomes 'rrr' (the three R's: writing, reading, arithmetic).
'e'+'rrr'='errr'
'o' going within 'errr' is 'ERROR'.
'putting' is the link.
(Other definitions for error that I've seen before include "Boob" , "Slip, mistake" , "Mistake or fault" , "wrongdoing" , "Way of operating" .)