English language Question...please help?

I would say most or all of these have no posiitve, comparative, or superlative degrees in the sense that most adjectives have. One says "foremost", "uppermost", "outermost", or perhaps "innermost" to denote superlatives for such adjectives. I have never heard a superlative or comparative for nigh. We would say "further in/ahead/up/out/" to denote comparatives for these words.