Correct

更 vs 更加 vs 还

/ gēng vs gèngjiā vs hái /
Strokes

Definition

更, 更加 and 还 are all Adverbs, which means “more; even more; still”.

Example

更 is used in comparison to indicate a further degree and functions as an adverbial. It can modify monosyllabic as well as polysyllabic words.
更加 means the same as 更, but more literary. It usually modifies polysyllabic words or phrases. 更加 can be used instead in example ②.

更大点儿 in example ③ cannot be replaced by 更加.
1
Zhèjiā
这家
shāngdiàn
商店
de
dōng
东西
jiā
hái
  
(
gēng
  
)
duō
  

The goods in this shop are much more than those in that one. (modifying the predicate)

2
Fēng
guā
de
gēng
  
(
gèngjiā
更加
  
)
hai
厉害
le
  

The wind is much stronger. (modifing the complement)

3
yào
zhāng
gēng
diǎnr  
点儿
de
zhuōzi
桌子
  

I need litle bigger table. ( modifying the attributive)

更加 can modify disyllabic words plus (一) 些.
4
jiào
比较
lai
起来
  
,
xiǎnde
显得
gèngjiā
更加
  
(
gēng
  
)
chéngshú
成熟
xiē
  

Comparatively, he looks much more mature.

更 and 更加 usually precede complements.
5
de
liǎn
脸色
biàn
de
gēng
  
(
gèngjiā
更加
  
)
nánkàn
难看
le
  

His face became much paler.

6
de
hàn
汉语
shuō
de
gēng
  
(
gèngjiā
更加
  
)
liú
流利
le
  

He speaks Chinese more fluently.

更加 can precede 变得, 说得, etc, this is a literary expression, while 更 cannot be so used like this.
7
Tīng
le
zhèhuà
这话
  
,
de
liǎn
脸色
gèngjiā
更加
biànde
变得
nánkàn
难看
le
  

Her face becomes even much paler at the words.

8
Shàng
le
yuè
de
péixùnbān
培训班
  
,
de
hàn
汉语
gèngjiā
更加
shuō
de
liú
流利
le
  

He speaks Chinese even more fluently after attending a training class of a month.

还 indicating that an action or state remains unchanged.
9
Tiānhēi
天黑
le
  
,
hái
zài
li
那里
děng
zhāo
  

It's dark, and he's still waiting there.

10
Tiān
天气
háiyào
还要
zài
lěng
tiān
  

The cold will last several another day.

还 indicating that a state remains unaffected by a certain factor.
11
suīrán
虽然
nián
年纪
le
  
,
shì
可是
dòngzuò
动作
hái
me
那么
língmǐn
灵敏
  

Though he is old, he is still agile.

12
bìngdǎo
病倒
le
  
,
hái
diàn
惦记
zhāo
gōngzuò
工作
  

Even if he fell ill, he still thought of this work.

还 indicating that a state remains unchanged though it should not be so.
13
hái
shuì
ne
  
,
kuài
chū
出去
kànkan
看看
  
!

You're still in bed. Hurry up and see what's happening outside.

14
Zhème
这么
wǎn
le
  
,
zěnme
怎么
hái
méi
zǒu
  
?

Why not leave for it's so late?

还 indicating supplement.
15
jiā
家里
yǒu
父母
  
,
háiyǒu
还有
liǎng
háizi
孩子
  

He lives with his parents and two children.

16
Xué
学习
hàn
汉语
  
,
chúle
除了
duō
tīng
duō
dòu
  
,
hái
de
duō
rén
shuōhuà
说话
  

Learning Chinese should practice speaking a lot besides listening and reading a lot.

还 indicating comparison.
17
Zhège
这个
rén
女人
nánrén
男人
hái
  
(
gēng
  
)
nénggàn
能干
  

The woman is more capable than a man.

18
Zhè
hái
méiyǒu
没有
nuǎnhuo
暖和
  

The room is not as warm as that one.

19
biān
xué
学习
biān
shuì
打瞌睡
  
,
hái
不如
xiān
chū
出去
zǒuzǒu
走走
  

He might as well go out for a walk, for you are dozing off over studying.

还 meaning something is not bad.
20
Cānjiā
参加
ge
那个
yànhuì
宴会
  
,
zhè
shēn
ban
打扮
hái
可以
  

You look nice in this dress for the feast.

21
Zhè
piān
bàogào
报告
xiě
de
hái
háng
  

The report is nice.

Sometimes in a sentence 还 is used first to introduce a striking example, then 更, etc. is used to emphasize the impossibility.
22
juéde
觉得
zhè
piān
wénzhāng
文章
nán
  
,
jiù
gēng
xíng
不行
le
  

If you think the article is difficult, let alone me.

23
Xiǎo
de
hái
mǎi
bu
  
,
de
jiù
gēng
yòng
不用
shuō
le
  

I cannot afford to buy the small one, let alone the bigger one.

Sometimes, 更 can be replaced by 还 because they both mean " comparison".
For example ①.
24
Zhèjiā
这家
shāngdiàn
商店
de
dōng
东西
jiā
hái
  
(
gēng
  
)
duō
  

The goods in this shop are much more than those in that one.

Sometimes, 更 can be used instead of 还, but 更 only means "a higher degree", while 还 implies "sth. extraordinary".
For example ⑰.
25
Zhège
这个
rén
女人
nánrén
男人
hái
  
(
gēng
  
)
nénggàn
能干
  

The woman is more capable than a man.