I'm reading "Immortals of Meluha" and while reading I encounter a sentence that was delivered by Shiva, he said "I'm no Lord Ram". What I'm thinking is that he should have said "I'm not Lord Ram". Correct me if I'm wrong.
They are both grammatically correct, but they can have subtly different meanings.
"I'm not Lord Ram" means that they are not the person named "Lord Ram".
"I'm no Lord Ram" can also literally mean they aren't Lord Ram, but more often is used to imply that they are very different from Lord Ram in some way.
- I have some basic medical knowledge, but I'm no doctor. (I'm not as good as a real doctor)
- You're smart, but you're no Einstein. (You aren't as smart as Albert Einstein.)
- Senator, you're no Jack Kennedy
Both sentences are grammatically correct. They mean different things.
The first sentence:
- I'm no Lord Ram.
means that "I" am different in an important way from "Lord Ram". Perhaps "Lord Ram" is much more powerful, or much wiser, or knows much more about the subject of the conversation. Or perhaps the difference is one of aptitudes or morals: "Lord Ram" might be much nicer, or much more courageous, or much nastier, or much more cowardly, et cetera. In effect, the sentence treats "Lord Ram" as epitomizing a category of individuals, and says that "I" am not a member of that category.
As the original poster suspects, the second sentence is simpler. Its meaning is obvious:
- I'm not Lord Ram.