1. Hardly had the train left when the conductor entered the compartment.
2. Hardly had we entered the hall when ...
3. Hardly had the writer pronounced his name when ....
4. Rudolf had hardly stepped on the landing when ...
5. Sherlok Holmes had hardly examined the crypt when ...
6. Hardly had Meeks finished the description of his sister's books when ...
7. My aunt had hardly moved in when ...