Table 7.

Removed types of errors

Type of error	Explanation, examples, and total error calculation
Tone discoloration	The letters “r” and “l” can discolorate the tone of certain grapheme or grapheme-clusters such as ee, oo, eu, ij, and ei. For instance, “veel” (a lot of) sounds like /vil/ with a slightly long stretched short vowel /i/. Errors: mostly the tone discoloration is not recognized and the short vowels are written down. For instance, “vil” instead of “veel.” Deleted because it could be classified as both morphological as orthographic.
Adhesive letters	In certain parts in the Netherlands, a schwa is added in between two consonants in the letter clusters with “r” (-rg/-rp/-rm/-rk/-rf) and with “l” (-lg/-lp/-lm/-lk/-lf). For instance, the word “tulp” (tulip) is pronounced /tulup/. A schwa is added between two consonants. Errors: the schwa is sometimes added in the written word, for instance “tulup” instead of “tulp.” Deleted because it could be classified as both morphological as orthographic or phonological error.
-ng/-nk	The grapheme-combination “-ng” and “-nk” are difficult because the sound is different from the known grapheme’s “n,” “g,” and “k.” The “ng” forms a new sound and the “nk” is pronounced like “ngk.” The sound and grapheme-combination have to be known by heart. Errors: mostly the “ng” is written like “n,” for instance “krin” instead of “kring” (circle). The “nk” is mostly written like “ngk,” for instance in “flingk” instead of “flink” (brave). Deleted because some schools treat it as a grapheme-phoneme correspondence whereas others see it as an orthographic word to remember.