This study investigates the nature of semantic compatibility between constructions and lexical items that occur in them in relation with language use, and the related concept, coercion, based on a usage-based approach to language, in which linguistic knowledge (grammar) is grounded in language use. This study shows that semantic compatibility between linguistic elements is a gradient phenomenon, and that speakers' knowledge about the degree of semantic compatibility is intimately correlated with language use. To show this, I investigate two constructions of English: the sentential complement construction and the ditransitive construction. I observe speakers' knowledge of the semantic compatibility between the constructions and lexical items and compared it with empirical data obtained from linguistic corpora and experiments on sentence processing and acceptability judgments. My findings specifically show that the relative semantic compatibility of the lexical items and the construction is significantly correlated with the frequency of use of their co-occurrences and the processing effort and speakers' acceptability judgments for the co-occurrences. The empirical data show that a lexical item and a construction which are less than fully compatible can be actually used together when the incompatibility is resolved. The resolution of the semantic incompatibility between the lexical item and its host construction has been called coercion. Coercion has been invoked as a theoretical concept without being examined in depth, particularly without regard to language use. By correlating degree of semantic compatibility with empirical data of language use, this study highlights that coercion is an actual psychological process which occurs during the composition of linguistic elements. Moreover, by examining in detail how the semantics of a lexical item and a construction interact in order to reconcile the incompatibility, this study reveals that coercion is semantic integration that involves not only dynamic interaction of linguistic components but also non-linguistic contexts. Investigating semantic compatibility and coercion in detail with empirical data tells about the processes by which speakers compose linguistic elements into larger units. It also supports the assumption of the usage-based model that grammar and usage are not independent, and ultimately sheds light on the dynamic aspect of our linguistic system. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]