Expressing "let alone" with "hekuang"

何况 (hékuàng) can mean "let alone" or "all the more". It can be used in the following structure:

Subject + 连 + A + 都 + Verb, 何况 + B + 呢？

呢 often appears at the end of this structure, to form a rhetorical question.

何况 can be used in two ways, the first of which where 何况 is used to emphasize that A is easier than B.

For example:

我连一千块钱的工资都赚不了，何况一万呢？(I can't even earn 1000 a month, and you saying I could earn 10000?)
小孩儿连说话都不会，何况背诵诗歌呢？(The baby can't even speak, and you're thinking he could recite poetry?)
你连这么简单的试题都不会，何况那么难的呢？ (You couldn't answer a question that easy, and you're kidding yourself you could answer one that hard?)

In the above examples: as A is so hard, B would almost be impossible.

This structure can be directly reversed to mean the opposite; that is, A is harder than B. For example:

我连一万块钱的工资都赚得了，何况一千呢？(I'm earning 10000 a month, and you're saying I couldn't even earn 1000?)
小孩儿连诗歌都会背诵，何况说话呢？(The child can even recite poetry, how could he not be able to speak?)
你连那么难的试题都不会，何况这么容易的呢？(You can answer questions that hard, how could something like this be hard for you?)

In the above sentences, as A is so easy, then B must be even easier.

何况 doesn't necessarily have to be used with the 连...都... structure, and can be used as a simple statement instead of a rhetorical question.

Some examples:

何况 is often used with 尚且, a formal way of saying 还. 更 can be added to 何况 to add further emphasis.

Sources and further reading

Chinese Grammar - Broken down into 100 items - Basic and Intermediate Levels (汉语语法百项讲练 - 初中级) pp. 278-279