Discussion Groups / ESL Teaching / February 2005

That would depend on what you are talking about when you use the
words.

expedite
1.    to speed up the progress of; hasten: to expedite shipments.
2.    to accomplish promptly, as a piece of business; dispatch: to
expedite one's duties.

Expedite is a word used in the business world and in government and
the military. It is often used to refer to the movement of orders,
paperwork or goods.

accelerate
1.    to cause faster or greater activity, development, progress,
advancement, etc., in: to accelerate economic growth.
2.    to hasten the occurrence of: to accelerate the fall of a
government.
3.    Mech. to change the velocity of (a body) or the rate of
(motion); cause to undergo acceleration.
4.    to reduce the time required for (a course of study) by
intensifying the work, eliminating detail, etc.

Accelerate can also be used to refer to speeding the movement of
orders, paperwork or goods. But it has in addition uses that you
wouldn't use 'expedite' for. Definition 3 for instance is a specific
physics and engineering term.

So you can either accelerate or expedite economic growth, or a course
of study, or a shipment of goods. But you only accelerate a car by
stepping on the throttle.