The first thing you need to realize is that "are" is a form of the English verb "to be". In Spanish there are two verbs for this one English verb. The first verb is "ser" and the second verb is "estar".
Let's look at the first Spanish verb for "to be", which is "ser". In Spanish, you use "ser" when you want to denote a permanent condition. For example, if you want to say that someone "is" a doctor, or someone "is" tall, then you would use "ser" because this is a permanent thing. That person will always be a doctor and that person will always be tall.
Sometimes we can be something for only a brief time, or just temporarily. In Spanish, we use the verb "estar" to describe a temporary condition. For example, if someone is happy or someone is walking, then this is a temporary thing. They won't always be happy and they won't always be walking. So we use "estar" because this is a temporary condition.
Now we conjugate the verbs "ser" and "estar". To say "are" with "ser" we say "son". To say "estar" we say "están". The accent in "están" means that the second syllable is pronounced with more emphasis.
Now you know how to say "are" in Spanish. But let's look at some samples. Remember in Spanish that pronouns aren't usually said. So the following are complete sentences:
TEMPORARY
están felices = they are happy
están caminando = they are walking
están tristes = they are sad
PERMANENT
son dentistas = they are dentists
son bajos = they are short
son capaces = they are capable
Now you know how to say "are" in Spanish. Good luck and have fun!
