Very often, we can use either expression. 'I used to walk home from work'. 'I would walk home from work'. These describe repeated actions and events in the past. But only 'used to' can refer to past states. 'I used to have a happy life' - not 'I would have a happy life'. We also use only 'used to' for regular and important habits - 'I used to smoke', not 'I would smoke'. Note that would can also be used as a conditional form - 'I would go on holiday if I had any money' etc. I hope that helps! Steve

"would" has multiple uses. In this context, "would" indicates a habit in the past which may or may not be a habit now. Example: Last year, my brother would walk to work. (= Last year, my brother always/usually walked to work. We don't know about now.) "used to" indicates a habit or state in the past which is no longer true. Example: Last year, my brother used to walk to work. (but not anymore) When my brother was a child, he was skinny (but not anymore)