Could is etymologically related to Will. Could is related to Possible. Possible is related to Accomplish. 
Throat is related to Voice. Voice is related to Noise. Noise is related to Smell. 
Will <--EtymologicallyRelatedTo-- Could <--RelatedTo--> Possible <--RelatedTo--> Accomplish 
Throat <--RelatedTo--> Voice <--RelatedTo--> Noise <--RelatedTo--> Smell 