when matters "este" when "sunteţi"?
For example: cine este in cameră? or cine sunteţi in cameră?
"Este" is used in the 3rd person singular, so when you are talking about a single person who is not yourself and who you're not talking to directly. "Sunteți" is used in the 2nd person plural. This means either when you are talking to a group of people or to a single or multiple persons in a formal manner.
To my understanding "cine este în cameră" is correct and "cine sunteți în cameră" is not. There could be another meaning that I'm not aware of though.
''este'' is singular and "sunteti" is plural the correct would be the 1st one "sunteti" can be also used in a formal way as in "sunteti bine imbracat (you are well dressed.)." but not in general questions questions
Este is the singular form of the english word who, while sunteți is the plural form of the word who.
I write here the conjugation of the verb to be in romanian. I am=eu sunt, you are (singular)=tu ești, he is=el este, she is=ea este, we are=noi suntem, you are(plural)=voi sunteți they are=ele sunt(feminine)/ei sunt(masculine).