哭个不停, 要玩就玩个痛快: V个 + complement
【高87】【高126】补语、紧缩复句 / complements
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
V + 个 + complement: here 个 counts nothing; it links the verb to a short fixed complement that says how far the action goes: 哭个不停 (cry non-stop), 说个没完 (talk on and on), 睡个够 (sleep one's fill), 问个明白 (ask until it is clear). It carries insistence, impatience or abandon.
The complement is a small word or fixed expression, such as 不停, 没完, 够, 痛快, 明白, 清楚 or 彻底. For a free adjective ("cry sadly") you go back to the complement with 得 (哭得很伤心, HSK 2); you never put 得 before 个.
The same 个 works in the squeezed sentence (要)V就V个 + complement, two clauses packed into one: "if you do V, do it properly". The verb is repeated after 就: 要玩就玩个痛快 ("if you're going to play, play all out"), 喝就喝个够. It urges someone to go all the way and is very colloquial. Do not confuse it with V就V，别……, whose second half is a prohibition.
Examples
那个小女孩哭个不停，怎么哄都没用。
Nàge xiǎo nǚhái kū ge bùtíng, zěnme hǒng dōu méi yòng.The little girl cried non-stop and nothing could calm her.
他在我们面前说个没完，谁也插不上嘴。
Tā zài wǒmen miànqián shuō ge méiwán, shéi yě chā bu shàng zuǐ.He went on and on in front of us and nobody could get a word in.
难得放假，我想睡个够。
Nándé fàngjià, wǒ xiǎng shuì ge gòu.It's rare to get time off, so I want to sleep my fill.
这件事我非要问个明白不可。
Zhè jiàn shì wǒ fēi yào wèn ge míngbai bùkě.I have to get to the bottom of this.
要玩就玩个痛快，工作的事明天再说。
Yào wán jiù wán ge tòngkuài, gōngzuò de shì míngtiān zài shuō.If we're going to play, let's play all out; work can wait until tomorrow.
喝就喝个够，今天不醉不回家。
Hē jiù hē ge gòu, jīntiān bú zuì bù huí jiā.If we're drinking, let's drink our fill: nobody goes home sober tonight.
Common mistakes
✗ 她哭得个不停。 → ✓ 她哭个不停。 (个 attaches straight to the verb, with no 得).
✗ 她笑个很高兴。 → ✓ 她笑得很高兴。 (after 个 only a short fixed complement such as 不停, 够, 痛快; an adjective with an adverb needs 得).
✗ 要玩就个痛快。 → ✓ 要玩就玩个痛快。 (the verb is repeated after 就).