When learning either a first or second language, the learner uses context clues, prior knowledge, and interaction with others to understand the new language. This is an important similarity for me to remember because I can build my lesson plans to incorporate all of these things. I also like the ESL Myth slide that reminded me that learning content is as important as direct ESL instruction. Providing context clues, prior knowledge, and interaction with peers will not only help students learn English but learn the appropriate math content (in my classroom) as well.
An obvious, but important, difference between first and second language acquisition is that while first language development happens "naturally" for (almost) everyone, second language development requires motivation and consistent effort on the part of the learner. Learning a first language happens gradually over time as you are learning to speak as a child. You have native speakers to practice with at home. Learning a second language requires effort, studying, and dedication. Learners may need to seek to find native speakers to practice with.
In terms of my personal experience - I hated trying to learn a new language. It did not come easily to me, and I lacked the motivation needed to be successful. (Now I wish I could speak Spanish!) I had the luxury of not needing to learn a new language because all of my education was instructed in my first language. I imagine if I was forced into a situation where I needed to go to school in another country (with another language), the motivation would have become intrinsic.
