Difference between 这个 and 本

Question

There are two words in Chinese that are both translated as “This” in English (这个 and 本). What is the difference between them and how to use them correctly ?

Answer 1

1. When 本 is used with an identity (person, company) it is exclusively referring to the first-person, and 这 is mostly referring to the third-person (some people do refer to oneself in the third-person)

Example:

这个人 (this person - the third-person)

这位法官 = this judge (the third-person)

这間公司 = this company (the third-person)

本人 = this person (the first-person) --> this person (I myself)

本官 = this judge (the first-person) --> this judge, (I myself)

本公司 = this company (the first-person) --> this company (our company)

Notice:

[本 + identity] is not always a "humbling word" for example 本大少爺 means 'This young master (I)'

2. 本 means 'this/ current' when it is used with time. The difference between [这个星期六，今個世紀 ，今年] and [本週六，本世紀，本年度] is the former is more colloquial and the latter is more literary

3. '本地' is a compound word meaning 'local/ domestic' (adj) e.g. '本地品牌' or 'this land'; 本土 is a compound word meaning 'native' e.g. 本土品牌 or 'mainland' e.g. 日本本土

Answer 2

Register.

这个 is neutral to colloquial in register, whereas 本 is very formal and almost exclusively used in writing.

此 and 该 are two other formal options, both roughly equal in formality to 本.

Note that 本 is also a classifier for things like books, so you may see something like 这本书. This usage is completely separate from the formal usage.