The difference between USED TO and WOULD 

 

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 quit 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.

 

 

Another good explanation on Would and Used to:

 

 

We use both of these to talk about things in the past which we don't do now or are not happening now. Sometimes both 'used to' and 'would' are OK in one sentence - sometimes only 'used to'.

Let's start with some examples of 'used to' first. We might say,

"I used to live in Manchester, but I moved to London last year."
"When he was at school, he used to play football every Saturday."
"She used to hate her job until she got a promotion."

All of these sentences describe actions or situations in the past, which are finished now; living in Manchester, playing football every Saturday, hating her job - these are all finished now.

We use 'used to' to talk about actions or situations that continued for some time in the past, not for events which happened suddenly or just for a moment. So we can't say: 'I used to have a really good idea when I was brushing my teeth this morning,' because 'having a really good idea' happens suddenly - in one moment.

Now let's move on to 'would'. Here are some examples:
"When he was at university, he would sleep until noon at the weekends."
"My sister lived in Australia for many years, but she would always come home for Christmas."
"I would always forget my homework, until the teacher threatened to punish me."

Again, these sentences are about situations in the past, which are finished. However, it's important to notice that all the sentences, here, are about actions or situations which were repeated again and again and again. Sleeping until noon at the weekends, coming home for Christmas, forgetting my homework - all these things were repeated many times, again and again and again.

This is the difference between 'would' and 'used to' -
We only use 'would' to describe actions or situations that were repeated again and again and again...
But we use 'used to' for any extended action or situation in the past.

'Would' is only good for actions or situations that were repeated many times;
'Used to' is good for any action or situation that continued for a period of time in the past, including repeated actions or situations.

To make this clearer, let's look at the three examples of 'used to' sentences, and see if we can change them into 'would' sentences.


Here's the first example again:
"I used to live in Manchester, but I moved to London last year."

Can we use 'would' instead of 'used to' here?
No, we can't, because 'living in Manchester' wasn't repeated again and again and again. It's simply a situation in the past. Therefore, only 'used to' is good in this sentence.

The second example again:
" When he was at school, he used to play football every Saturday."

Here, we're talking about 'playing football every Saturday'. This is an action that was repeated many times, so we can also say:
"When he was at school, he would play football every Saturday".
'Used to' and 'would' are both good here, and the meaning is the same.

Finally, the third example again:
"She used to hate her job until she got a promotion."

Did she 'hate her job' many times?
No, this isn't a repeated action, so in this example 'would' isn't possible. We have to use 'used to'.