The concept of "antonym" is used for properties, not for objects (or, in grammatical terms, for adjectives and adverbs, not for nouns).

There is a particle called an "anti-neutron", but that can hardly be considered an antonym.

defination of grammatical weight

No. The word to is a grammatical particle. It is used BESIDE a verb to form an infinitive, which a compound form of verb. For example: to see, to sleep, to go, to write, and so on. But the word to per se is not a verb.

To use "grammatical" in a sentence, you could say: "She always makes sure her sentences are grammatically correct." This showcases the use of the word "grammatical" in the context of proper sentence structure.

No this is not grammatical. The correct phrase is "did he wake up?"