Abstract 1. Introduction 2. The Competition Model as a Functionalist Approach to Language Acquisition 3. Basic Tenets of the Competition Model 3.1. Two-level Mapping 3.2. Cue Validity 3.3. Cue Strength 3.4. Conflict Validity and Overall Validity 3.5. Learning-on-error Mechanisms 3.6. Cue Cost 4. Empirical Studies Conducted Within the competition Model 5. Conclusion References