Practise the thinking. Keep the judgement.
寂しい (sabishii): Lonely; desolate
さびしい
sabishii
Meaning
Lonely; desolate
Two original examples
友だちが引っ越して、寂しいです。
I feel lonely because my friend has moved away.
誰もいない駅は寂しかったです。
The empty station felt desolate.
Usage and distinctions
寂しい has the readings さびしい and さみしい. It can describe a lonely feeling or a quiet, desolate place. 悲しい means sad more broadly; the words overlap in some situations but are not identical.