The Perfect Tenses include:
Think of them as the complete tenses as they describe a finished activity.
The Perfect Tenses are formed using the perfect aspect.
The perfect aspect is the combination of conjugated auxiliary verb to have and active verb's past participle. The verb to have detemines whether a sentence has
a present (have/has seen), past (had seen) or future (will have seen) meaning.
If we combine the continuous and perfect tenses, we get: