“That” and “Who” are English words that are used in sentences. That and who are pronouns. Pronouns are words used instead of a noun.
That and who are used to express a person or a thing. That and who are relative pronouns. Relative pronouns act as a substitute for a noun and also acts as a word use to join two clauses together.
They are used together most times.
For example, who gave that boy my pen?
However, their major difference is that “WHO” is used is used to relate to a person only for example, who locked the door while “THAT” is use to relate to a person or an object.
For example, that car is faulty (an object) and that man is my father (a person).
That and Who are pronouns and they are used to represent nouns. It is important to understand how the pronouns 'that and who' are used in different ways to form sentences. Just like we have types of pronouns like possessive pronouns, personal pronouns and demonstrative pronouns, ‘that and Who' also belong to a type of pronoun called relative. They are used in joining two clauses in a sentence and after which they attach the relative clause to the noun or pronoun they modify.
A sentence might seem incomplete if 'that or who' are not in the right place in a sentence. However, there are some differences between them. The word 'that' is a pronoun used in place of a noun that is either a person or a thing. The word 'who' is also a pronoun used to refer to only a person. Aside from the fact that 'that' is a relative pronoun, it can also be used as a conjunction, adjective and adverb. While 'who' are most times used as object or subject of a verb.