Dear Sir / Ma'am,
English dictionaries and grammar books say the word 'only' in the followig sentence is an adverb.
Only God can make a tree.
In the above sentence, I can fully understand that the word of only modifies, or limits the word of God which is a noun. But I can not understand that they call it an adverb instead of an adjective.
I would appreciate it if you kindly explain the reason why the word of only in the above sentence is called an adverb instead of an adjective.