Until he reached the coast, equiano reports that he was able to understand the language of the people he lived with. what can you infer from this? his group was widespread and most owned slaves. he had never really traveled very far from his home village. each village had its own dialect of a common african language. his kidnappers were not aware that he belonged to a related people.

From the lines, we can infer that Each village had its own dialect of a common African language.
The phrases He was able to understand the language . Indicates that Equiano experience a certain degree of hardship in understanding the language.
But since there is no indicators that Equiano has knowledge in another language, we can infer that it's same basic core language only with different dialect