By oneself and Only

Only and by oneself are semantically related in alone topic. In some cases you can use "Only" instead the phrase "By oneself" as an adverb or an adjective.

Only adjective - Having no equal or rival for excellence or desirability.

By oneself and only are semantically related in singular topic. Sometimes you can use "By oneself" instead the word "Only" as an adjective or an adverb.