The Past Perfect Continuous and Past Perfect are both used to talk about actions that happened before another action in the past, but they have different focuses.
Past Perfect Continuous: This tense emphasizes the duration or ongoing nature of an action that was happening before another past action. It is formed using "had been" + the verb ending in -ing.
Example: "I had been studying for two hours when she called."
Conditions to Use:
- Use it when you want to highlight how long an action was happening before something else occurred.
- Often used with time expressions like "for," "since," or "when."
Past Perfect: This tense focuses on the completion of an action before another action in the past. It is formed using "had" + the past participle of the verb.
Example: "I had finished my homework before she called."
Conditions to Use:
- Use it when you want to emphasize that an action was completed before another past action.
- It can be used with time expressions like "before," "after," or "by the time." (however, these time expressions can also be used with the Past Perfect Continuous tense, for example, "By the time he arrived, she had already been watching TV".)
In summary, use Past Perfect Continuous for ongoing actions with emphasis on duration, and Past Perfect for completed actions.
