[Lingo] ensure/guarantee

["Stephen J. Turnbull" <stephen@example.com>]

Nguyen Vu Hung writes:
 > Hi all,
 > 
 > Would anyone tell me what the difference between the following words.
 > 
 > ensure: 保証する、請け合う確保する
 > guarantee: 保証する、請け合う

Formally, a guarantee is legally enforceable.  Closely related to
"warrantee".  "Ensure" is just a statement about what you've done.

Informally, if there is any difference, a guarantee is a promise to
ensure, basically.  "I've ensured that the bug won't happen again"
leaves me with no responsibility if my patch fails, but "I guarantee
that ..." implies a promise to fix it.  In practice, there's no
difference in informal talk.