1. Navajo Code Talkers

2. Navajo Code: How it works
The Navajo Code uses a combination of acronyms and word replacements.
Plain text when encrypted could be spelled out in English and for each letter acronyms would be used.
Most commonly used military terms and key subjects would be with a symbolic word.
Navajo Code Talkers WWII
Windtalkers

3. For example
If the plain text is ‘Drop.’ It would be translated into English cipher text first: D -> Deer R -> Rabbit O -> Owl P -> Pant

4. Those words would now be translated into Navajo:
Deer = BE Rabbit = GAH Owl = NE-AHS-JAH Pant = CLA-GI-AIH The resulting transmission: BE GAH NE-AHS-JAH CLA-GI-AIH

5. Replacing Entire Words
Not all words are transmitted in such a way.
Entire words are replaced with Navajo words that have a different literal meaning.
Since it is a spoken language and it does not have words that directly correspond to modern warfare and military terms, words in the traditional language are used to represent modern terms and names. 
For example:
'tank' would be referred to as a 'turtle‘
'submarine' would be referred to as 'iron fish'
'bombs' (carried on aircraft) would be called 'eggs'. 

6. Encode a Message
With a partner, write out a sentence using 8-12 words relating in some way to WWII.
Note that there are no numbers in the dictionary, so they would have to be spelled out.
Names of people would also have to be spelled out.
Now encode your message, using one line per word and using the alphabet for any words not in the dictionary.