不定詞to+動詞，或動名詞v＋ing，皆可作句子主詞或補語或受詞等用途，請問其區分及不同點在那？

Reference to your recommended bk by TW Chen's the heart of grammar , which part of speech do you not understand ?! infinitive adj, n (grammar) in English is non-finite form of a verb used with or without to,eg:-to know how to do the responds ; to go to camping today ; to clean the classroom, let Kuangkwo go ; allow him kk to go today; gerund is the form of a verb when used as a noun eg:-the -ing form of an English verb when used as a noun(as in "enjoy playing on-line game").as in "hate for being not polite in respond", as in" Let the state of being infinitive".