adjective, stur·di·er, stur·di·est. strongly built; stalwart; robust: sturdy young athletes. strong, as in substance, construction, or texture: sturdy walls.

Is sturdy a adverb?

In a sturdy manner.

Is sturdily a adverb?

sturdily adverb – Definition, pictures, pronunciation and usage notes | Oxford Advanced Learner’s Dictionary at OxfordLearnersDictionaries.com.