This is what kids develop in their native language during their early lives. ELs develop this 2-3 years into learning.
Cognitive Academic Language Proficency
This is academic language, and not everyday language. ELs develop this after 5-7 years.
Comprehensible Input Hypothesis
Stephen Krashen
Input Hypothesis
Learning must be engaging to be successful. The result of this would be the EL understands what we tell them.
Affective Filter Hypothesis
Stephen Krashen
Bored or anxious ELs = higher filter
Comfortable and relaxed ELs = low filter
Critical Period Hypothesis
Eric Lenneberg
This theory states the optimal time when to teach L2.
The optimal time is between age 2 and puberty.
Common Underlying Proficency / Transferability Theory
In the world, skills and concepts are similar no matter the language. Once the EL understands the necessary vocabulary, those
skills/concepts can transfer over from the L1 to the L2.