Not to mention/let alone

Not to mention +n/v-ing更不用说，更别提mention 提及，说到I can’t even solve the math problem, not to mention the 8-year-old kid.我都算不出来这道数学题，更别说这个8岁的孩子了。He is a rich guy, he has a luxury car, not to mention 2 houses in Beijing.他可是个土豪，他有辆豪车，更不用提他在北京还有2套房子。let alone 一般用于否定句的后面，表示后面的情况更不可能。she can't even make instant noodles, let alone cook a meal.她连下方便面都不会，更别说做饭了。He may never be able to walk again, let alone play football.他可能再也站不起了，更别说踢足球了。