example is derived from the Old French essemple, which can be traced back to the Latin exemplum, which has the same semantics as "example;."instance;Examples". So the "for example" meaning for example is logical.
When I see instance, I think of instant. Instant can be used as an adjective, a noun, and an adverb with meanings related to "instant, instantaneous, short-term", which are a bit distant from the instance for instance (for example).
Instance is derived from the Latin noun instantia, which means presence, effort, intention; earnestness, urgency。
In addition to the above meanings, instantia is also a transliteration of the ancient Greek word enstasis. Along this path, the instance has a fact, a case, an example, which is why for instance has the meaning of an example (1650s). 19c begins with the generic meaning of anything that illustrates a general type.
Historically, the earliest use case for example is 1584, and for instance is 1657.
Mainstream dictionaries almost all paraphrase the two phrases to each other, so there is no significant difference in semantics.
Someone checked the network data and found that for example is more popular than for instance. In classic English-speaking countries such as the United Kingdom, Australia, and New Zealand, the frequency of for example is 7 to 11 times that of for instance, while for non-English-speaking countries such as India and South Africa, the proportion drops to 3 to 4 times.
For the "Corpus of Contemporary American English", the proportion found was three times higher.
So while there is no difference in semantics between for for Exclusive and for instance, people prefer to use the former.
For example is an abbreviation for for the sake of an example (see for exampleWhat does for instance mean?).)。Since it is an abbreviation, the grammatical rules are not followed, so there is no article before the exmaple. Not only that, but multiple instances are also plural, such as [example sentence 1] a lot of my friends were there—John and Linda, for example(A lot of my friends are there, like John and Linda.) )