tier 1 words are words we speak and hear every day:
came
went
dinner
haircut
language
Tier 2 words are more difficult words that we probably know but students may not; however they come across them when reading age appropriate text
-compost
-fertilization
-logistics
-cumbersome
tier 3 words are generally words you might need for a particular story or passage. They are low frequency words
-spelunker
-hydrogenous
and other big words that Teacher Groupie uses