I have a sentence which is "He said false sentence". Does this sentence Sound NATURAL? How can I create the most natural version of it using the words in the quotation marks? Ps: It meant to say his sentence was not correct. Thanks in advance for the answers.
Sentence is a countable noun, so requires an article in the singular. It is usually used only when we are talking about the language - the specific words and grammar - not about the meaning.
Say usually takes as object either a that clause, or a direct quotation, or something (usually followed by a qualification or relative clause). Examples:
He said that he was not coming.
He said "That's wrong".
He said something [that] I didn't understand.
Following it with another kind of noun phrase (as "a false sentence") is not idiomatic.
You probably want:
He said something false.
He made a false statement.