Past Simple Vs Past Perfect Simple

Forms

Past Simple

P: Subject + verb past simple + ….

N: Subject + did + not + verb base + ….

Q: (Wh-) Did + subject + verb base + …?

Present Perfect Simple

P: Subject + had+ V past participle + …. .

N: Subject + had+ not + V past participle + …. .

Q: (Wh-) + had+ subject + V past participle + ….?

Use: Past perfect simple actions happened before past simple actions. 

1. He had left home when I arrived.
2. Before he divorced her, he had paid all the debts for the family. 
3. After he had removed the old tires, he cleaned all the rims.