Abstract Word comprehension is a complex process that requires several different skills, including morphological knowledge. This study examines the relationship between students’ word comprehension and their morphological knowledge and assesses how morphological knowledge differs for students with weak and strong word comprehension. The research questions to be answered are (1) What is the relationship between morphological knowledge and word comprehension in students in grades 2 and 4?  (2) How do students with strong word comprehension differ from students with weak vocabulary comprehension in terms of their results on a word inflection test? These questions were answered using a quantitative approach to data analysis. The results show that word comprehension correlates with morphological knowledge in students in grades 2 and 4. Students with a strong understanding of word comprehension also show stronger results on a word inflection test. The results of the study indicate that word comprehension and morphological knowledge are related to each other, which leads to discussions about to what degree morphology should be part of vocabulary instruction. This study argues that instruction in morphology will help students comprehend words and enhance vocabulary development, not least for students with word comprehension difficulties.

Spelling is known to be a very complex ability that includes many different cognitive and language skills. The purpose of the study was to (1) investigate the correlation between students’ spelling and morphological knowledge in grade 2 and grade 4, and (2) study the differences between poor and advanced spellers in regards to phonemic awareness and word decoding. A quantitative method was used, which included systematic testing that meausered students’ spelling, morphological knowledge, phonemic awareness and word decoding, among other. The participants were 46 students in grade 2 and 37 students in grade 4. The results of the study show positive correlations between students’ spelling and morphological knowledge, which agrees with previous studies that have shown that morphological knowledge has a positive impact on students’ spelling. The results also show a difference between poor and advanced spellers, whereupon poor spellers scored low in both phonemic awareness and word decoding, and vice versa. Overall, the resultats shed additional light on the complex process of spelling and can inform special needs teachers regarding how morphological awareness has the potential to support students with spelling difficulties.