The word "persons" is used largely in formal writing, particularly in a legal context. It would pretty much never be used in informal speech or writing, at least not in US English. "People" would always be used in such situations. The word "persons" is most often used when writing of a limited, but perhaps indefinite, number of people. when speaking of large group, such as a nation, an ethnicity, or humanity in general, "people" would normally be used.

The idea that " 'people' should never be used to describe people you know or when you attach a number to it." is simply not correct, at least not in US English.

There are 3 people who are bachelors in my family.

Is a perfectly natural and grammatical sentence. If "persons" were used instead, it would sound a bit affected in informal speech or writing, in my view.

Fifty people were killed in the explosion.

would be a natural sentence in a newspaper report. "50 persons" would not.

Except in a strictly legal or other technical context, "people" can be used almost anywhere that "persons" is used.

Exception: In christian theology, one writes "Persons of the Trinity" not "People of the Trinity".

###People as a Plural of Person###

Merriam-Webster gives as meaning 2 under Noun:

plural : human beings, persons —often used in compounds instead of persons

Dictionary.com gives as senses 1 and 2:

persons indefinitely or collectively; persons in general: to find it easy to talk to people;

What will people think?

persons, whether men, women, or children, considered as numerable individuals forming a group:

Twenty people volunteered to help.

The Cambridge Dictionary givea as the first meaning>:

men, women, and children generally; pl of person:

• There were a lot of people there.
• Some people were hurt.

The Oxford Dictionaries says:

The words people and persons can both be used as the plural of person, but they have slightly different connotations. People is by far the commoner of the two words and is used in most ordinary contexts: a group of people; there were only about ten people; several thousand people have been rehoused. Persons, on the other hand, tends now to be restricted to official or formal contexts, as in this vehicle is authorized to carry twenty persons; no persons admitted without a pass

The word "persons" is used largely in formal writing, particularly in a legal context. It would pretty much never be used in informal speech or writing, at least not in US English. "People" would always be used in such situations. The word "persons" is most often used when writing of a limited, but perhaps indefinite, number of people. when speaking of large group, such as a nation, an ethnicity, or humanity in general, "people" would normally be used.

The idea that " 'people' should never be used to describe people you know or when you attach a number to it." is simply not correct, at least not in US English.

There are 3 people who are bachelors in my family.

Is a perfectly natural and grammatical sentence. If "persons" were used instead, it would sound a bit affected in informal speech or writing, in my view.

Fifty people were killed in the explosion.

would be a natural sentence in a newspaper report. "50 persons" would not.

Except in a strictly legal or other technical context, "people" can be used almost anywhere that "persons" is used.

Exception: In Christian theology, one writes "Persons of the Trinity" not "People of the Trinity".

###People as a Plural of Person###

Merriam-Webster gives as meaning 2 under Noun:

plural : human beings, persons — often used in compounds instead of persons

Dictionary.com gives as senses 1 and 2:

persons indefinitely or collectively; persons in general: to find it easy to talk to people;

What will people think?

persons, whether men, women, or children, considered as numerable individuals forming a group:

Twenty people volunteered to help.

The Cambridge Dictionary gives as the first meaning:

men, women, and children generally; pl of person:

• There were a lot of people there.
• Some people were hurt.

The Oxford Dictionaries says:

The words people and persons can both be used as the plural of person, but they have slightly different connotations. People is by far the commoner of the two words and is used in most ordinary contexts: a group of people; there were only about ten people; several thousand people have been rehoused. Persons, on the other hand, tends now to be restricted to official or formal contexts, as in this vehicle is authorized to carry twenty persons; no persons admitted without a pass

The word "persons" is used largely in formal writing, particularly in a legal context. It would pretty much never be used in informal speech or writing, at least not in US English. "People" would always be used in such situations. The word "persons" is most often used when writing of a limited, but perhaps indefinite, number of people. when speaking of large group, such as a nation, an ethnicity, or humanity in general, "people" would normally be used.

The idea that " 'people' should never be used to describe people you know or when you attach a number to it." is simply not correct, at least not in US English.

There are 3 people who are bachelors in my family.

Is a perfectly natural and grammatical sentence. If "persons" were used instead, it would sound a bit affected in informal speech or writing, in my view.

Fifty people were killed in the explosion.

would be a natural sentence in a newspaper report. "50 persons" would not.

Except in a strictly legal or other technical context, "people" can be used almost anywhere that "persons" is used.

Exception: In christian theology, one writes "Persons of the Trinity" not "People of the Trinity".

The word "persons" is used largely in formal writing, particularly in a legal context. It would pretty much never be used in informal speech or writing, at least not in US English. "People" would always be used in such situations. The word "persons" is most often used when writing of a limited, but perhaps indefinite, number of people. when speaking of large group, such as a nation, an ethnicity, or humanity in general, "people" would normally be used.

The idea that " 'people' should never be used to describe people you know or when you attach a number to it." is simply not correct, at least not in US English.

There are 3 people who are bachelors in my family.

Is a perfectly natural and grammatical sentence. If "persons" were used instead, it would sound a bit affected in informal speech or writing, in my view.

Fifty people were killed in the explosion.

would be a natural sentence in a newspaper report. "50 persons" would not.

Except in a strictly legal or other technical context, "people" can be used almost anywhere that "persons" is used.

Exception: In christian theology, one writes "Persons of the Trinity" not "People of the Trinity".

###People as a Plural of Person###

Merriam-Webster gives as meaning 2 under Noun:

plural : human beings, persons —often used in compounds instead of persons

Dictionary.com gives as senses 1 and 2:

persons indefinitely or collectively; persons in general: to find it easy to talk to people;

What will people think?

persons, whether men, women, or children, considered as numerable individuals forming a group:

Twenty people volunteered to help.

The Cambridge Dictionary givea as the first meaning>:

men, women, and children generally; pl of person:

• There were a lot of people there.
• Some people were hurt.

The Oxford Dictionaries says:

The words people and persons can both be used as the plural of person, but they have slightly different connotations. People is by far the commoner of the two words and is used in most ordinary contexts: a group of people; there were only about ten people; several thousand people have been rehoused. Persons, on the other hand, tends now to be restricted to official or formal contexts, as in this vehicle is authorized to carry twenty persons; no persons admitted without a pass