Would or Used to?

Weslei in Brasil writes:
I've seen lots of explanations about the usage of would and used to but I'm still confused. What does, exactly, "past states" mean? Is there a "short cut" which I could easier identify when "would" could not be used? I also observed that, most of the times, "would" (meaning "used to") comes in the same sentence with a time reference (My mother would bake me a cake whenever I visited her.) . Is there anything to do with a short cut or was it just a coincidence?

I love this kind of question because I've never thought about these usages before.

You're right: When we're talking about some past state of affairs, and we use would, we usually give a time reference:
When I lived in Mexico City, I would take the streetcar to visit my friend in San Angel.
When our kids were little, I would get up with them on Sunday mornings so their mother could sleep.
On Thursdays, I would take the ferry to Sechelt.

If we didn't give the time reference, it would be easy to misunderstand:
I would take the ferry to Sechelt. (When? Why? What's keeping you from doing so?)

"Used to" is more flexible. We don't need a time reference:
I used to live in Mexico City.
I used to get up with my kids on Sundays.
I used to take the ferry to Sechelt.

But we can also use it in place of "would":
When I lived in Mexico City, I used to take the streetcar ...
When our kids were little, I used to get up...
On Thursdays I used to take...

Comments

[Brett]

I'm not sure if this is generally true or not. There is a good discussion of the differences in _The Grammar Book_ by Marianne Celce-Murcia and Diane Larsen-Freeman. They point out that 'used to' is often used to introduce a story, while 'would' is often used to expand on it (e.g., When we were young, we used to visit the cottage every year. We'd play in the surf...).