Comma at the end of a sentence?

Solution 1:

It is a phrase that attaches itself at the end of a regular sentence:

"Her name is Mary." + "right?"

The main sentence is complete in all respects.

The phrase that comes in is "attached" using a comma.

"Her name is Mary, right?"

"right?" here is known as a 'question tag.' Notice that this is always an interrogative (question).

See Wikipedia

A question tag or tag question is a grammatical structure in which a declarative statement or an imperative is turned into a question by adding an interrogative fragment (the "tag"). For example, in the sentence "You're John, aren't you?", the statement "You're John" is turned into a question by the tag "aren't you". The term "question tag" is generally preferred by British grammarians, while their American counterparts prefer "tag question".