You should not believe in him because he is a pseudo.
「你不應該相信他,因為他是個騙子。」
附加
我們可以用下面的單字來表達謊言的「假裝」:
impostor (騙子)
She claimed she was a teacher who could help me learn Spanish, but she turned out to be an imposter. She is still a university student and hasn’t got a license to be a teacher yet.
「她聲稱自己是一位老師,可以幫助我學西班牙語,結果她是個騙子。她還是大學生,還沒考到老師的證照。」
knockoff(仿冒品)
My brother accidentally bought a knockoff that looked very similar to the actual designer bag for his wife.
「我哥哥無意中幫他太太買了一個跟真正的名牌包非常像的仿冒品。」
counterfeit (贗品)
The police seized a shipment of counterfeit Japanese cars at the airport.
「警方在機場查獲一批假的日本汽車。」
Faux (人造的)
Our floor at home is made with faux marble.
「我們家的地板是用人造大理石製成的。」
Wannabe (隨意表達、Want to be 的縮寫)
She pretended to be an idol and wore a school uniform, but she’s just a wannabe singer. She’s an adult and graduated from school a long time ago.
「她假裝自己是偶像,穿著校服,但她只是一個想成為歌手的人。她已經是成年人而且早就從學校畢業了。」