confused! wet vs dry crackles

i thought that i understood crackles but now am confused.

when i have a chf patient and i hear crackles, is this considered wet or dry crackles? am i correct in assuming that these are wet crackles since the fluid is backing up into the lungs and i am hearing the air moving through the fluid?

when i have a pneumonia patient what kind of crackles am i hearing? is it dry due to the infection blocking off a good portion of the lower lungs, or wet due to the air traveling through the mucus of the infection.

is it possible to distinguish wet from dry crackles primarily by auscultation, or do they both sound the same via stethascope?

help! and thanks!

tt