This is how I explain the past perfect. 
 My diagram uses colour to demonstrate the auxiliary verb and past participle. 
 includes a fully conjugated present simple and past simple 
 includes a fully conjugated present perfect and past perfect to highlight the difference in formula between the present and past perfect (with a focus on the auxiliary verb HAVE). 

the-past-perfect-formula-and-comparison-to-the-present-perfect_162965.docx

The past perfect formula and comparison to the present perfect

the-past-perfect-formula-and-comparison-to-the-present-perfect

Let's do English ESL grammar guide. This is how I explain the past perfect. 
 My diagram uses colour to demonstrate the auxiliary verb and past participle. 
 in…