Building blocks added at the beginning of a word (prefix(e)s):

be-
bi-
co-
chief- (head of)
de- (undo)
do-
dis-
e-(electronic)
ex- (former)
female-
fore-
grand-
in-
male-
mal- (ungood)
mis (uncorrect)
new-
no-, not-
online-
pre- (before in time)
pro- (in favour of)
re- (recurrent)
Synglish-
tech-
tri-
u- (under)
un- (opposite)