“As” can be used with the meaning of “in the role of”. “Like” can be used to compare a thing with an other thing. But the sentence “I am as strong as an elephant.” doesn't mean that I'm in the role of an elephant. An alternative formulation of the sentence could be “I am srong like an elephant.”, which features the comparative “like”. What is the meaning of the first “as” and what is the meaning of the second “as”? I am ecpecially interested in the difference of the meanings of the second “as” and a comparative “like” because I'd like to know if “as … like …” is possible or why it isn't possible.