Summary:
1. Causing of the mistakes: Almost every word in the examples are rendered, which makes them wordy and clumsy. The translators of such signs are making their efforts to be faithful to the original, without considering the time and space limitation.
2. Ways of avoiding such mistakes: The core message should be recognized and translated, others to be cut off. The translators should value the translation from the target readers’ perspective, and had better to show the translation to a foreigner to see the response. If the response is negative, then revisions should be made until it is satisfactory.

4.1.4. Inappropriate tone of speech
The language used on signs should be friendly and polite, especially for the restricting ones, such as “keep distance” (保持车距) , “ticket only” (凭票入场) etc. It is found that the problem of using inappropriate tone of speech is prevalent in restricting public signs, which makes the target readers feel uncomfortable or offended.

Example 21                                              
  


(Shot in the Summer Palace)

Analysis: “Forbidden” is defined as “not permitted, especially by law” (http://dictionary.cambridge.org/define.asp?key=78416&dict=CALD, which is too strong for a regulation of a park, and will make the readers feel uncomfortable. “请” in the original makes the sign seem friendly, while in English, no equivalence for this word is found, hence seem impolite.
“In case of” used to describe what you should do in a particular situation, especially on official notices. This phrase often indicates something bad or unexpected, for example, “in case of fire”, “in case of emergency’ etc. The Chinese equivalence of this phrase is “万一”, so if we back translate this sign into Chinese, it will be read as “万一发生罚款，请勿入内”, which will be not understandable to anyone.
Suggestions: “No Admittance”.

Example 22


(Shot in a scenic spot)

Analysis: This public sign is served as a reminder to the visitors, reminding them that it is dangerous to go across here because the steps are wet and slippery. The intention of the sign is to show the care to visitors, while the English reads like a compelling. The original intention has been deviated.
What’s more, “slidy” is a self-made word, which can’t be found in any English dictionary.
Suggestions: “Slippery road ahead! Keep away from it!”

Example 23

(Shot in a Xihaizi Park in Tongzhou District)

Analysis: “Halt” is used as either a military command or prevent someone from continuing with something, which is not suitable in this situation, and appears to be so strong. In addition, words used on signs should be familiar and understandably, for this, “stop” is better than “halt”.
Suggestion: In this situation, negative sentence can be replaced by positive expression, which is more acceptable. “Staff only” is the best choice.

Example 24


(Shot in a museum in Literature Museum)

Analysis: “No touch” is acceptable internationally, and can be understood by target readers with no problem. The only problem is that the direct “no” on the sign is a little bit too strong, which can be revised to please to readers.
Suggestion: “Hand off!” will be all right.

Example 25

(Shot in a park in Chaoyang District)

Analysis: The sign which stands beside a lake in a park is set up with an intention to warn the visitors that they should take care when walking around the lake. In this case, imperative sentence should be used instead of a declarative one like this.
It is wrong to use “carefully” here, which is the adverb form of “care” and means “小心地” in Chinese. Foreigners may burst into laugh when catch sight of such a sign, because the back translation of it is read as “小心地掉到水里”, which is quite opposite to the original intention.
Suggestion: “Dangerous! Keep off the water!”