First of all, common noun trademarks are not distinctive enough. The Trademark Law stipulates that “Article 8 is any visible sign that can distinguish the goods of a natural person, legal person or other organization from the goods of others, including Text, graphics, letters, numbers, three-dimensional logos and color combinations, as well as combinations of the above elements, can be applied for registration as trademarks.

Article 9 The trademark applied for registration should have distinctive features that are easy to identify. It shall not conflict with the previously acquired legal rights of others.

The trademark registrant has the right to indicate "registered trademark" or registered mark.

Article 10 The following signs shall not be used as trademarks. :

(1) Identical or similar to the country name, national flag, national emblem, military flag, medals of the People's Republic of China, as well as the same name or landmark building in a specific location where the central state agency is located The names and graphics are the same;

(2) The names, national flags, national emblems, and military flags of foreign countries are the same or similar, except with the consent of the government of that country;

(3) ) is the same as or similar to the name, flag, or emblem of an intergovernmental international organization, except with the consent of the organization or if it is not likely to mislead the public;

(4) It is the same as the official sign indicating the implementation of control and guarantee, The inspection marks are the same or similar, except those authorized;

(5) The names and signs of "Red Cross" and "Red Crescent" are the same or similar;

(6) Ethnically discriminatory;

(7) Exaggerated and deceptive propaganda;

(8) Harmful to socialist morals or having other adverse effects

Place names of administrative divisions at or above the county level or foreign place names known to the public shall not be used as trademarks. However, place names with other meanings or as components of collective trademarks or certification marks shall not be used; registered place names shall not be used as trademarks. The trademark shall continue to be valid.

Article 11 The following marks shall not be registered as trademarks:

(1) Only the common name, graphics and model of the product;

(2) Only directly express the quality, main raw materials, functions, uses, weight, quantity and other characteristics of the goods;

(3) Lack of distinctive features

If the marks listed in the preceding paragraph have acquired distinctive features through use and are easy to identify, they may be registered as trademarks.

Article 12 Where a trademark is applied for registration as a three-dimensional mark, the shape or shape is caused only by the nature of the goods themselves. The shape of goods that is necessary to obtain technical effects or that makes the goods of substantial value shall not be registered.

Article 13 A trademark applied for registration on the same or similar goods is a copy, imitation or translation of others. Well-known trademarks that have not been registered in China and are likely to cause confusion will not be registered and are prohibited from use.

If the trademark applied for registration for different or dissimilar goods is a copy, imitation or translation of a well-known trademark that has been registered in China by others, misleading the public, and causing the interests of the registrant of the well-known trademark to be potentially damaged, Registration is not allowed and use is prohibited. "

As for the noun you said cannot be registered, it should be that the noun has already been registered, so it definitely cannot be registered. As for the analysis of economics, I am sorry for my lack of knowledge. You see, "Apple" is Noun, can’t it be used to apply for a trademark?