Is there any different meaning between using 真 and 真的 in a sentence?
When 真 is used as an adjective, or adverb here in all your examples, &quot;的&quot; can sometimes omitted. When &quot;的&quot; is used however..in my personal opinion it just makes the sentence longer and sometimes you could emphasize the tone on &quot;真的&quot;. When emphasized in an question, it'll feel like you're surprised someone really don't know the subject. When emphasized in a plain sentence it'll feel like you're emphasizing you really don't know it.
But if you're using it as a noun, then it's just &quot;真&quot;
Some examples:#
&quot;不知道這個新聞的真假&quot; (used as noun)
&quot;不知道這個新聞是真的假的&quot; (used as adjective)
&quot;真(的)不知道這新聞的真假&quot; (used as adverb first, then noun at the end)