Using data from the 400-million-word Corpus of Historical American English (COHA) and the 450-million-word Corpus of Contemporary American English (COCA), this study investigates both diachronically and synchronically the use of the -free compound and its counterparts, the free of/from phrases. A close examination of the frequency, distribution, and structural and semantic functions of the constructions yields the following key findings. First, frequency-wise, free of has exhibited a steady slow growth, and free from has declined dramatically; in contrast -free has increased enormously, although its archaic use in the senses of ‘free to' and ‘free with' disappeared by the 1940s. Second, the -free compound boasts a high potential productivity index. Third, while both the compound and the phrasal constructions may be used as predicative and postnominal adjectives, objective complements, and adverbials, only the -free compound is used as a prenominal (attributive) adjective. Fourth, whereas the -free compound is used almost exclusively nonreferentially, the free of/from constructions are used significantly more referentially. Fifth, even in the contexts where the constructions may all be used, often only one is allowed or preferred due to certain internal structural and semantic factors. Finally, condensation of information along with changes in language and life styles appears to have driven the increased use of the compound over its phrasal counterparts, although the phrase free of charge has resisted the change: its high frequency likely has blocked its *charge-free compound counterpart.