`1`. hadn't started
`2`. had taken
`3`. had been preparing
`4`. had arranged
`5`. had spied
`6`. had been shouting
`7`. hadn't eaten
`8`. had been crying
`9`. had been writting
`10`. hadn't been sleeping
----------------------------------
+) Past perfect tense: S + had + PII + O
+) Past perfect continuous: S + had been + Ving + O