Tickets are valid for any number of rides within a time limit (so yes, you can transfer).
The time limit depends on the type of ticket.
The standard ticket will pass additional validations for one hour after first use. The ticket needs to be validated at the beginning of each ride only—it doesn't matter how long the ride takes. You can get on a bus (and re-validate you ticket) 1 minute before the ticket expires, and get off half an hour later.
There are other tickets that may me more advantageous. For example, the evening ticket (soirée) is valid from 7 PM until the end of service that day.
Ticket machines do have an English interface.