easy to understand易懂的，容易理解的
B2 You say that something, for example someone's behaviour, is understandable, if you feel that it is usual and not strange or difficult to understand合乎情理的；正常的；可以理解的
Her reluctance to talk to the press was quite understandable.
His reaction is understandable in the circumstances.
The instructions must be understandable to those who are using the system for the first time.
I wasn't surprised at her response, it was perfectly understandable.
an understandable attitude/concern