Your daughter was probably confusing “object” and “predicate” These two concepts are different in English grammar. In “the pen is blue”, “blue” is not an object for two reasons: 1. As others have pointed out, it’s an adjective, not a (substantive) noun. 2. Even if it were a noun, the verb “to be” can never take a direct object. In a sentence like “She is a student”, the word “student” is not the object of “to be”, but rather a predicate nominative (also called a “subject complement” these days). This is why we are supposed to say “it is I” rather than “it’s me”. Note that in real life, “it’s me” is in fact very common, but this is not really an object; it's actually an example of an “emphatic pronoun” — a grammar point borrowed from French (thank you William the Conqueror). In your sentence, the correct term for “blue” would be the “predicate adjective”. For further information, you can do a web search on the terms I’ve mentioned, and / or come to me for further information.

Hi to you both! The short answer: 'blue' is an adjective and you're right that a an adjective can't be an object. The long answer: 'Blue' isn't an object in this case, it's a predicate adjective. Adjectives can be attributive ('the blue pen'), appositive ('the pen, blue in the sunlight'), or predicate (as in your example). You're right, in that a true adjective (as opposed to an adjective used substantively - 'the good man' versus 'the good') can't really be an object in itself, but it can still feature in an objective sense, as it follows the case of noun. If I were parsing your sentence, I'd say 'pen' is subject nominative and 'blue' is an adjective agreeing with 'pen' in the predicate position. If your sentence were, 'I like the blue pen', then 'blue' wouldn't in itself be the object of the sentence, but it occupies the same grammatical position as the pen itself - it would be an attributive adjective, in agreement with 'pen', the direct object of 'like'. Happy to clarify more, if this doesn't answer your question!

Fun with grammar! "Blue" can be an adjective, a noun, and a verb. I like the blue pen. [subject = I / verb = like / object complement = the blue pen] [blue = adjective modifying the object "pen"] I like blue. [subject = I / verb = like / object complement = blue] [blue = noun] The pen is blue. [subject = I / linking verb = is / subject complement = blue] [blue = adjective modifying the subject "pen"] The blacksmith blued the iron sword. [subject = the blacksmith / verb = blued / object = the iron sword]

My answer is who gives a flying f***. In China they get way over excited about technical grammar. To drive a car you don't have to know what the bits of the engine are called.

To keep it simple ....... the pen is an object (it is tangible - you can touch it), blue is not an object, therefore the pen is the object.