but

Here are some examples of this form:
Being nice to someone is a SIMPLE BUT EFFECTIVE WAY of making friends.
Some herbs like MOIST BUT WELL-DRAINED SOIL.
I am making SLOW BUT STEADY PROGRESS with my language learning.
Although she is usually easy to get along with, she does have a RARE BUT SERIOUS SIDE to her personality too.
A SMALL BUT SIGNIFICANT NUMBER of students didn’t pass the test.