更不用说 (gèng bùyòng shuō) means "let alone," and is used in the same way as the English, where we might say: "he can't even boil an egg, let alone prepare a banquet"
Structure
连 + A + 都 / 也 + Verb， 更不用说 + B + 了
Notice that the order used in this pattern is the opposite to the 别说 structure.
Examples
- 他 都 不 会 煮 鸡蛋， 更不用说 做 一 大 桌子 的 菜 了。 He can't boil an egg, let alone prepare a banquet.
- 他 连 自己 国家 的 国旗 都 不 认识， 更不用说 其他 国家 的 了。 He can't even recognize his own country's flag, not to mention any other countries' flags.
- 他 从来 没有 出 过 远门， 更不用说 出国 了。 He's never traveled very far, let alone out of the country.
Unless the first action is negated with 没有, using 更不用说 generally requires using 了 to emphasize that the speaker is adding his/her own comment.
See also
Sources and Further Reading