It depends on what he's talking about. A standard single shot of espresso is about 7g[0] for 30 mL. A double espresso takes 14g to 18g of coffee[1] for 60 mL. A latte or cappuccino is just an espresso with some form of milk. A caffe Americano is an espresso in hot water. Traditionally brewed coffee should be 10g per 125 mL of water before brewing[2] which should be 20g to 30g for a basic mug, but 8g can be perfectly reasonable for many types of "civilized" coffee.
0: https://coffeefaq.com/many-ounces-shot-espresso/
1: https://www.seattlecoffeegear.com/learn/videos-home/ask-the-...
2: https://coffeefaq.com/just-how-much-ground-coffee-do-i-need-...