In Chapter 3, Cooper introduces a dialect of his own invention that he claims is a representative translation of American Indian speech in what we now call upstate New York:
“Even your traditions make the case in my favor, Chingachgook,” [Hawkeye] said, speaking in the tongue which was known to all the natives who formerly inhabited the country between the Hudson and the Potomac, and of which we shall give a free translation for the benefit of the reader; endeavoring, at the same time, to preserve some of the peculiarities, both of the individual and of the language.
Cooper is probably referring to Algonquian languages, which are not a single language but rather the interrelated languages of many American Indian tribes in this region. Cooper was influenced by American Indian languages, but his "free translation for the benefit of the reader" is a conceit of the novel: recall that Cooper is a novelist, not a historian. He is telling a fictional story to capture a sense of history rather than documenting events that really happened. There is no source text he is translating. It is all made up.
The dialect Cooper uses to represent Algonquian speech patterns is characterized by grandiose references to nature and history. For instance, Hawkeye continues:
Your fathers came from the setting sun, crossed the big river, fought the people of the country, and took the land; and mine came from the red sky of the morning, over the salt lake, and did their work much after the fashion that had been set them by yours; then let God judge the matter between us, and friends spare their words!
The gist of what Hawkeye is saying is that Chingachgook's people came from the west, and Hawkeye's people came from the east (across the ocean) to conquer the land in the region. He claims that both groups have undertaken similar projects of conquest, and that it is now up to God to decide who will prevail. Chingachgook pushes back on Hawkeye's narrative here, largely claiming that guns have given white colonists an advantage. Even Chingachgook's pushback does not address all the tenuous pieces of Hawkeye's equivalency between American Indians and European colonists. For instance, American Indian peoples have lived in the region far, far longer than European colonists and would likely not use the idea of conquest to describe their relationship to the land. By cloaking Hawkeye's speech in the flowery "Algonquian" dialect, Cooper passes him off as a white man who has assimilated to American Indian culture and ideology. Closer examination reveals that Hawkeye might not be as assimilated as he thinks.
In Chapter 5, just after Hawkeye and the Mohicans have saved Duncan from Magua's treachery, Duncan encourages the party to run after the fleeing Magua. Hawkeye responds with a metaphor emblematic of his invented dialect:
“Why so soon disheartened!” he exclaimed; “the scoundrel must be concealed behind some of these trees, and may yet be secured. We are not safe while he goes at large.”
“Would you set a cloud to chase the wind?” returned the disappointed scout[...]
Duncan is right that the party is not safe while Magua is "at large," but Hawkeye's metaphor makes clear that it is a moot point. Telling a cloud to chase the wind would be impossible because it is the wind that propels clouds. Likewise, it would be impossible for the party to chase Magua, even if they know he is nearby. Magua's actions will determine what the band of travelers does for the rest of the novel. Magua is the wind, and the travelers are a cloud.
Hawkeye could just as easily have told Duncan more straightforwardly that Magua is practiced at moving stealthily through the woods, and that a large party is unlikely to catch up with him. His use of a metaphor echoes the way the Mohicans speak, through a great deal of figurative language. Cooper has already established that metaphors are the building blocks of their language, and that he has attempted to preserve this style in his "translation" of their dialect. Hawkeye's liberal use of metaphors signifies that despite his whiteness, he is a product of Mohican culture.
