Five main hypotheses:
• The acquisition-learning hypothesis
• The monitor hypothesis
• The natural order hypothesis
• The input hypothesis
• The affective filter hypothesis.
• Subconscious process
• Similar to learning native language
• Conscious process
• “Rules" and "grammar“
• Formal instruction
• Less effective than acquisition (according to Krashen)
Acquisition – Learning Distinction
Picking up words
• Relationship between acquisition and learning.
• The acquirer/learner must know the rule.
• The acquirer must be focused on correctness.
• Having time to use the monitor.
Natural Order Hypothesis
• The acquisition of grammatical structures follows a
“natural order” which is predictable.
• He rejects grammatical sequencing.
• Teaching of grammar can result in language acquisition
– when students are interested.
• Structure that is “a little beyond” where we are now.
• “going for meaning” first.
• Speaking fluency cannot be taught directly.
• Provide comprehensible input.
Affective Filter Hypothesis
• ‘Affective variables’: Motivation, self-confidence and
• Learners with these affective variables are better
The acquisition-learning hypothesis is at the core of
modern language acquisition theory, and is perhaps the
most fundamental of Krashen's theories on second
• Krashen, Stephen D. Principles and Practice in
Second Language Acquisition. Prentice-Hall
• Krashen, Stephen D. Second Language Acquisition
and Second Language Learning. Prentice-Hall