Change vs. no change

If things have not changed or the situation still remains the same, hái 还 is usually used. Compare the following pairs of sentences.

1.1

Yǐqián tā hěn pàng, xiànzài tā shòu le
以前他很胖，现在他瘦了。
Before he was fat, (but) now he has become thin.

1.2

Yìqián tā hěn pàng, xiànzài tā hái hěn pàng.
以前他很胖，现在他还很胖。
He was fat before (and) he still is now.

2.1

Yǐqián tā hěn xǐhuan hē jiǔ, xiànzài tā bù xǐhuan hē le.
以前他很喜欢喝酒，现在他不喜欢喝了。
Before he used to like to drink, (but) now he doesn't any more.

2.2

Yǐqián tā hěn xǐhuan hē jiǔ, xiànzài tā hái hěn xǐhuan hē jiǔ.
以前他很喜欢喝酒，现在他还很喜欢喝酒。
Before he used to like to drink, (and) he still does now.

3.1

Yǐqián tā xué Zhōngwén, xiànzài tā bù xué le.
以前他学中文，现在他不学了。
He used to study Chinese before, (but) now he doesn't.

3.2

Yǐqián tā xué Zhōngwén, xiànzài tā hái xué.
以前他学中文，现在他还学。
Before he used to study Chinese, (and) he still does now.