Used to and would are both use to describe something that
happened regularly in the past but doesn't happen any longer, as shown in
the following two sentences about quitting smoking:
1.
I used
to smoke, but I gave up last year.
2.
Whenever I craved
a cigarette, I would chew gum instead.
However, there are two important differences
between used to and would. The
first difference is that would should not be used unless
it has already been established that the time frame is in the past,
while used to does not require this. This example,
with used to at the beginning, sounds natural:
- I used to watch cartoons every
Saturday morning when I was very little. Now I rarely watch TV.
However, when used to is replaced
with would, the same example becomes awkward and ungrammatical:
- *I
would watch cartoons
every Saturday morning when I was very little. Now I rarely watch TV.
But if the past time frame is established before would appears,would sounds
fine.
- When I was little, I would get
up and watch cartoons every Saturday morning. Now I rarely watch TV.
The second difference between used to and would is
that would is not used with stative verbs such as love,
be, understand, and feel. Compare these two sentences with the
stative verb love:
1. When I was a student, I used to love sleeping
late on the weekends. (natural and grammatical)
2. *When I was a student, I would love sleeping
late on weekends. (awkward and ungrammatical)
To summarize, the use of would is
more restricted than that of used to. Therefore, if you aren't
sure which one to use, it's best to choose used to.
(Adapted from http://www.learnersdictionary.com/qa/the-difference-between-used-to-and-would)
Here you have some exercises to practise: