It seems to me that Samuel’s speech contains linguistic and rhetorical elements which suggest that he may not have been a native Nephite speaker or that he may have grown up using a different dialect. If so, that might have made it difficult for Nephite people to understand or accept him. As you read Samuel’s words, listen for patterns of speech that might have struck his audience as unusual or “different.” Indeed, it would be surprising if the dialects spoken by Samuel and by the people in Zarahemla had not diverged over time from each other. If so, this language barrier could have added to the rejection of Samuel’s message by the people in Zarahemla.
In addition, there appears to have been certain stylistic elements that may have put some of his listeners off even further. For example, Samuel’s repetition of groups of words sometimes sounds redundant. In some instances, he repeated the same idea several times. He hovered over a point and repeated words in a staccato style. This could be a natural inclination of speakers of a second language when emphasizing a main point. Such speakers usually operate in the second language with a limited vocabulary. They reuse the same words, without speaking in flowery perlocutions, eloquent synonyms, or subtle euphemisms.
As a result, we can see in Samuel’s words indications of very straight-forward public speaking. The Nephite anti-Christs and other enemies of the church were often described as “flattering” and eloquent with their language. This is not said of Samuel, who may not have had that kind of training in Nephite oratory. What he did have was the truth, and he spoke it directly. Whether he had picked up the Nephite dialect or accent since his conversion or had been taught the language since birth, by the time he boldly addressed the people of Zarahemla, he had come to know the spirit of prophecy, to recognize the voice of his Lord Jesus Christ, and to understand certain Nephite scriptures very well.