Not for real
Student or Learner
I wonder how to call this kind of person.
He/she will never act according to what he/she really think; for example,
A : Hey, you see that guy in the corner? He is hot!
B : Oh.. not really. Just a little less than average (but actually she's thinking about how to approach him and get his cell number.)
After having homemade cooking,
A : How was my food?
B : Oh! It's terrific food I've ever had! (But she's actually thinking that 'Darn! It was soooo bitter!)
Is there any specific expression for this kind of person in English?
Please let me know.
Not for real
Thank you, susiedqq. I get it. : )
Another way to characterize the person in your first example is to say, "She plays her cards close to the vest." This implies that the person does not reveal her opinions/intentions easily. It does not have the same connotation as the very useful terms suggested by susiedqq; it is more neutral in tone.
[The reference is to a card player who never lets the other players see her cards.]
The person in the second example could also just be called polite. It all depends on the intention of the speaker.
Other possibilities might be: tactful, considerate. (These are positive traits.)
If it's a person who flatters another in hopes of gaining something from that person, there are the colorful terms toady, kiss-up, sycophant. (There are lots more of these. I will leave it to others to add to the list.)
Million thanks, Petra.
What you added above is very good enough for me. : )