PAST PERFECT and PAST SIMPLE (HAD | HAD HAD): what's the difference?

What's the difference between 'had' and 'had had' in English? The first one is the past simple and the second one the past perfect. But how do you use them correctly? Watch my video to find out! Join my English Grammar Programme: Lower-intermediate level (A1-A2): https://englishwithaga.com/great-gram... Upper-intermediate level (B1-B2): https://englishwithaga.com/great-gram... My English courses: https://englishwithaga.com/english-co... Free English grammar booklet: https://5minutelanguage.ck.page/gramm... My Instagram:   / english.with.aga