不定式可做定语也可作目的状语,具体情况具体分析,如I have many things to do.(to do作things的后置定语,作定语一般放在名词或代词后)I must get up early to catch the early bus.(本句中的不定式作目的状语,早起的目的是赶上早班车,可用于句首或句末)