I was actually thinking that what should I use?
You are doing great!
That means you are currently doing great! But if I use
You've been doing great!
That means you were doing great from the very beginning.
I was actually thinking that what should I use?
You are doing great!
That means you are currently doing great! But if I use
You've been doing great!
That means you were doing great from the very beginning.
As I mentioned in my comment, the usage depends in reference to the context of where it is used. Both sentences are grammatically correct and can be used. But then again, it depends on where you are using it.
You are doing great.
This sentence uses present continuous tense. It represents an action that is happening now and might continue in the near future.
You have been doing great.
This sentence uses present perfect continuous/progressive tense. It denotes, as you said, something that started in the past and is continuing at the present time. Now the thing to notice is that, past can be many years ago, several months ago, or just a few days ago.
Now if you wish to denote a habitual action, something that always happens no matter the circumstances, you can choose simple present tense. For e.g.
You do great/ He does great/ They do great.
For more reference you can read these blogs. Present Perfect Continuous Tense, Present Continuous Tense, Simple Present Tense.
"You have been doing great" implies it has been that way for a while, but it definitely doesn't have to mean from the beginning. It can have a sense of "you've been doing great recently", as a contrast with earlier. It can also have a sense of "up to now" implying that this might change, so they have to keep it up!
I feel like "you are doing great" is more positive - it's a statement about the person, there's no time period implied (as you get with perfect tenses) so there's no sense of contrast, no implication that things have changed or will in the future.
If you want to say they've been doing well the entire time, you could just say that explicitly - "you've done great since the beginning", something like that. Or you could just say "you're great at this!"