"She used to pay when we went to the restaurant."
Translation:Elle payait quand nous allions au restaurant.
Indeed lorsque and quand are very similar. It means that there is a time connection between two actions. However lorsque usually implies a stronger connection for me.
Just an example:
- Je regarde la télévision quand je rentre chez moi le soir. => I watch television in the evening after getting back home.
- Je regarde la télévision lorsque je rentre chez moi le soir => I (almost immediately) watch the TV when I enter my place (probably that I fear the TV could have been stolen )
In the case of the restaurant here, lorsque would sound weird because it is not a precise time connection but a general circumstance.
(I hope to be clear enough...)
Thanks for your attention, mon professeur, Sitesurf. The English version doesn't seem to imply the repeated actions. "we went to the restaurant" (nous sommes allés au restaurant) & "she used to pay" (elle payait). So "when we went to the restaurant, she used to pay" (Quand nous sommes allés au restaurant, elle payait).