Indefinite Pronouns in Tagalog, also known as panghalip na walang tiyak, are types of pronouns that give flexibility to the language as they do not refer to specific things or people and are often used for general references. They can be used to refer to ‘anybody’, ‘someone’, ‘nobody’ etc. such as “mayroon” (someone), “bawat isa” (anyone), “walang” (none), “lahat” (all) etc. Learning these indefinite pronouns is important in mastering the Tagalog language and its grammatical structure.