You need to know what action a sign tells you to take.
Picture the idea
Some labels are one character: 推 = push; 拉 = pull. Learn full warning phrases too. A familiar character inside an unfamiliar warning does not establish that it is safe to proceed.
Useful words
推
tuī
push
A door action.
拉
lā
pull
The opposite door action.
禁止
jìnzhǐ
prohibited
A warning starter.
入内
rù nèi
enter inside
In 禁止入内: do not enter.
小心
xiǎoxīn
be careful
A caution starter.
地滑
dì huá
slippery ground
小心地滑 = caution: slippery floor.
可以进去
kěyǐ jìnqu
may go inside
A permission question when followed by 吗.
Read the display
标志 · sign
位置 · example location
推
tuī
push
门
mén
door
拉
lā
pull
门
mén
door
禁止入内
jìnzhǐ rù nèi
no entry
通道
tōngdào
passageway
小心地滑
xiǎoxīn dì huá
caution: slippery floor
地面
dìmiàn
floor surface
Find the information
Which sign means you should not enter?
拉
小心地滑
禁止入内
Answer and explanation
禁止入内
禁止 = prohibited; 入内 = enter inside. Together it forbids entry.
Build your request
May + enter + question. Ask staff when permission is uncertain.
可以进去吗?
Kěyǐ jìnqu ma?
May I go inside?
The sentence pieces
可以
kěyǐ
may
进去
jìnqu
go inside
吗
ma
yes-no question
Understand the reply
不可以。
Bù kěyǐ.
No, that is not allowed.
What does this reply mean?
You may enter.
You may not enter.
The floor is wet.
Answer and explanation
You may not enter.
No, that is not allowed.
好的。
Hǎo de.
Okay.
Use it in another situation
Practice identifying 推 and 拉 without translation, then read the complete warning. If a real warning is unclear, stop and ask instead of guessing from a fragment.