Key Concepts in Second Language Acquisition and Cognition

Differentiation in Language Learning

Differentiation occurs when one category in the L1 corresponds to two or more categories in the L2. For example, English has one verb "to know," but Catalan differentiates this meaning into two verbs: saber and conèixer. An English speaker learning Catalan must learn to distinguish between these two verbs where English has only one. For this reason, differentiation is considered the most difficult category in the learning hierarchy.

Working Memory and Language Acquisition

Working Memory (WM) is a limited cognitive system that temporarily stores and processes information at the same time. In Second Language Acquisition (SLA), it allows learners to hold linguistic information in mind while understanding, comparing, and producing language. Learners with greater working memory capacity benefit more and more durably from interaction and feedback, while learners with lower WM show only short-term gains.

The Stroop Test and Attentional Control

The Stroop Test is a cognitive task where participants are asked to name the color of the ink a word is printed in while ignoring the word's meaning. It measures:

• Inhibition: The ability to suppress irrelevant information.
• Attentional Control: The ability to focus on relevant information and ignore distractions.

Modern Language Aptitude Test (MLAT)

The MLAT measures a learner's ability to learn a foreign language rather than their current proficiency. It consists of several parts:

• Recognizing and remembering sounds.
• Identifying grammatical functions in sentences.
• Memorizing word-meaning pairs.
• Inferring rules from examples.

The Accessibility Hierarchy

The Accessibility Hierarchy is a language universal proposed by Keenan and Comrie. It predicts which types of relative clauses a language can form and how easy they are to acquire. The hierarchy orders relative clauses from most accessible to least accessible:
Subject > Direct Object > Indirect Object > Object of Preposition > Genitive > Object of Comparative.

Contrastive Analysis Hypothesis (CAH)

The Contrastive Analysis Hypothesis claims that similarities between a learner's L1 and the target language make learning easier, while differences between the two languages cause difficulty and lead to errors due to negative transfer from the L1. According to the CAH, by comparing the L1 and L2, researchers and teachers can predict which errors learners will make in the L2.

The Aspect Hypothesis

The Aspect Hypothesis states that L1 and L2 learners initially use tense–aspect morphology according to the inherent lexical aspect of verbs, rather than purely grammatical tense. In the early stages of acquisition:

• Past/perfective forms first appear with achievement and accomplishment verbs.
• Imperfective/progressive forms first appear with states and activities.