Declarative knowledge is conscious, explicit, stateable knowledge — knowing that something is the case, as opposed to knowing how to do something. In language learning, declarative knowledge includes: knowing that Japanese verbs conjugate by replacing the -u ending of the dictionary form; knowing that 猫 (neko) means cat; knowing that the subjunctive in Spanish uses a different set of endings than the indicative. This contrasts with procedural knowledge — the automatic, implicit ability to use language fluently without consciously accessing rules. A learner may have declarative knowledge of a grammar rule but be unable to apply it in real-time conversation.

In-Depth Explanation

The declarative/procedural distinction:

The distinction originates in cognitive psychology, particularly in John Anderson’s ACT-R (Adaptive Control of Thought — Rational) model of cognition (1982, 1983). Anderson proposed that:

• Declarative memory: Stores factual knowledge (episodic and semantic facts) that can be consciously accessed and verbalized.
• Procedural memory: Stores “condition-action” rules (IF this context, THEN this action) that operate automatically without conscious access.

In skill acquisition, skills typically begin as declarative (“First I do X, then Y, then Z”) and, with sufficient practice, undergo proceduralization — the declarative form is compiled into procedural routines that execute automatically. The classic example: learning to drive involves initially explicit declarative knowledge of each action; experienced drivers execute the same actions procedurally without conscious attention.

Declarative knowledge in SLA:

In SLA, the declarative/procedural distinction maps onto the explicit/implicit knowledge distinction:

The interface debate:

A central question in SLA is whether declarative/explicit knowledge can convert into procedural/implicit knowledge through practice — and if so, whether this is the same implicit knowledge as that acquired through naturalistic input exposure.

• No interface position (Krashen): Explicitly learned rules (“learned” knowledge in Krashen’s terms) never convert to the implicit learned system (“acquired” knowledge). They are separate systems.
• Weak interface position (Ellis, N.): Explicit knowledge can indirectly facilitate acquisition by directing attention (noticing) to relevant input, which is then acquired implicitly through exposure.
• Strong interface position (DeKeyser): With sufficient practice, explicitly learned rules can become automatized and function as implicit procedural knowledge for production. Skill Acquisition Theory (DeKeyser, 1997 onward) supports this view.

The consensus in cognitive SLA research leans toward the weak interface — declarative knowledge can direct attention and accelerate implicit acquisition, but fully automatized implicit knowledge ultimately requires meaningful input exposure that is more than mere declarative practice.

Declarative knowledge’s role:

Even in immersion-based approaches that minimize explicit instruction, declarative knowledge still functions:

• A grammar explanation provides a declarative map that allows the learner to notice relevant patterns in exposure
• Vocabulary definitions provide declarative anchors that subsequent exposure consolidates into lexical procedural access
• Noticing errors (whether produced by self or others) is a declarative process that can influence subsequent acquisition

History

The declarative/procedural distinction in cognitive science traces to Ryle (1949, “knowing how” vs. “knowing that”), formalized computationally in Anderson’s ACT framework (1982). Application to SLA developed through R. Ellis’s distinction between explicit and implicit knowledge (1990s), DeKeyser’s skill acquisition framework (1997 onward), and Ullman’s declarative/procedural model of language in the brain (2001, 2004), which claims that lexical knowledge is supported by declarative memory and grammatical computation by procedural memory — and that L2 late learners rely more heavily on declarative memory for both.

Common Misconceptions

• “If you know the rule, you can apply it.” Declarative knowledge of a rule does not automatically produce procedural ability to apply it fluently. Many learners can state the “-te form” rule perfectly while still failing to produce it in real-time conversation.
• “Grammar study is useless.” Declarative grammar knowledge is not directly useless — it can direct attention and support noticing. The problem arises when learners treat declarative knowledge as the end goal rather than as a scaffold.
• “Declarative knowledge will convert to fluency if you study enough grammar.” Without substantial meaningful exposure and use of the language, declarative grammar knowledge stays declarative rather than becoming procedurally automatized.

Practical Application

• Use declarative knowledge strategically: learn grammar rules to understand the structure of exposure, not to memorize conjugation tables for test performance.
• After encountering a grammar point declaratively (through a textbook or explanation), seek exposure to that pattern in authentic material to begin the proceduralization process.
• Don’t expect rule-based accuracy under communicative pressure — procedural automatization requires many hours of exposure and practice.

Related Terms

• Procedural Knowledge
• Explicit Learning
• Implicit Learning
• Explicit Knowledge
• Implicit Knowledge
• Skill Acquisition Theory
• Noticing Hypothesis

Sources

• Anderson, J.R. (1982). “Acquisition of cognitive skill.” Psychological Review 89(4): 369–406. — foundational ACT-R model.
• DeKeyser, R. (1997). “Beyond explicit rule learning.” Studies in Second Language Acquisition 19(2): 195–221. — skill acquisition in SLA.
• Ullman, M.T. (2001). “The declarative/procedural model of lexicon and grammar.” Journal of Psycholinguistic Research 30(1): 37–69. — neurocognitive model applied to language.
• Ellis, R. (2004). “The definition and measurement of L2 explicit knowledge.” Language Learning 54(2): 227–275. — explicit knowledge in SLA.