Beginner level

(Difference 4) A determiner cannot be used as a subject complement.

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  Normal adjective: She is intelligent.
  

(The normal adjective intelligent can be used after a linking verb (here, is) and function as a subject complement.)

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  Determiner: She is [nothing fits here].
  

(You can't use a determiner as a subject complement. NB: If you think you've found a determiner that fits, then you've found a pronoun not a determiner.)

Below is a brief description of the main determiners. (There is a separate page on each one.)

Possessive Determiners. The possessive determiners (called "possessive adjectives" in traditional grammar) are my, your, his, her, its, our, their, and whose. A possessive determiner sits before a noun (or a pronoun) to show who (or what) owns it.

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  When a man opens a car door for his wife, it's either a new car or a new wife. (Prince Philip)
  
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  The only time a wife listens to her husband is when he's asleep. (Cartoonist Chuck Jones)
  

Read more about possessive determiners/adjectives.