HSK 6 grammar · conjunction
不是…，还/还是…
不是…，还/还是… — it isn't just X; you still need Y
Pattern
+ +
+ +
( ) can be left out · other words may come before, between and after
How it works
Rejects an over-simple premise and then supplies what is still required: 不是读完了就可以了，还应该写一篇作文 — "it isn't that finishing the reading is enough; you should write an essay too". The first clause names what someone is wrongly treating as sufficient, and 还/还是 adds the part they have skipped. ⚠️ The 还是 here is not the 还是 of a choice question — nothing is being offered as an alternative.
Examples
不是读完了就可以了，还应该写一篇作文。
Bú shì dú wán le jiù kěyǐ le, hái yīnggāi xiě yì piān zuòwén.
It isn't that finishing the reading is enough — you should write an essay as well.
这事不是你想做就能做的，还是要听听老板的意见。
Zhè shì bú shì nǐ xiǎng zuò jiù néng zuò de, háishi yào tīngting lǎobǎn de yìjiàn.
This isn't something you can just do because you feel like it — you still need to hear the boss out.
减肥不是少吃就行了，还得每天运动。
Jiǎnféi bú shì shǎo chī jiù xíng le, hái děi měi tiān yùndòng.
Losing weight isn't just a matter of eating less — you also have to exercise every day.
Related
See it in a story
In the app, 不是…，还/还是… is underlined wherever it appears in the stories you read, and practised with sentences from them. Free.