What type of spelling error is represented by the intended word "slapped" and the child's spelling "slapt"?

The intended word "slapped" and the child's spelling "slapt" represent a phonetic error. This type of error occurs when a student spells a word based on how it sounds rather than its correct spelling. In this instance, the child has simplified the complex spelling of "slapped" to focus only on the sounds they perceive, resulting in "slapt." This reflects an understanding of the phonetic structure of the word, but a lack of knowledge regarding its complete orthographic representation.

Morphemic errors relate to mistakes in the use of prefixes, suffixes, or roots, which is not applicable here since the child didn't alter the morphemes but rather omitted the additional sound that signifies the past tense. Semantic errors involve misunderstandings of meaning, while orthographic errors pertain to mistakes in following the conventional spelling of words, which could also apply, but in this case, it is specifically phonetics that drives the child’s spelling choice.