Grammar is probably the wrong word, but it seems like the question is about word identification, which relates to how spoken and written language interacts.

For instance, a local dialect may choose a different set of sounds for a word but maintain the same logogram as other dialects, so there is greater mutual intelligibly across the written language over the spoken language. In contrast, an alphabet written language encodes the sounds into the written text, so the written word looks different across different dialects reflecting the spoken language.