何况 / 况且: let alone / besides
连词 / conjunctions
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
何况 makes an a fortiori argument: if even A (easy case) is a problem, all the more so B (harder case), "let alone", "much less". The first part often has 连…都 or 尚且; the sentence often ends in 呢.
况且 ("besides, moreover") adds one more reason to back up a decision. 更何况 can also mean "all the more since".
Examples
这种垃圾连专家都分不清，何况普通人呢？
Zhè zhǒng lājī lián zhuānjiā dōu fēn bu qīng, hékuàng pǔtōngrén ne?Even experts can't sort this kind of rubbish, let alone ordinary people.
今天太晚了，况且还下着雨，明天再去吧。
Jīntiān tài wǎn le, kuàngqiě hái xià zhe yǔ, míngtiān zài qù ba.It's too late today, and besides it's raining: let's go tomorrow.
保护环境是大家的事，更何况这关系到我们的孩子。
Bǎohù huánjìng shì dàjiā de shì, gèng hékuàng zhè guānxi dào wǒmen de háizi.Protecting the environment is everyone's business: all the more since it concerns our children.
Common mistakes
✗ Using 何况 with the easier case: ✗ 大人都搬不动，何况大力士？→ what follows 何况 must be the harder case (✓ 何况孩子).
✗ 况且 doesn't do a fortiori; it only adds a reason.