The present study aims to investigate the phonological development of typically developing monolingual Swedish speaking children aged three to four years. The result could be used in the standardization of a new phonological test material for clinical speech and language pathology assessments. One-hundred and thirty four children aged three and four years (73 girls and 61 boys) were assessed with the new material. The children were tested in kindergartens in three communities in southeastern Sweden. Their assessments were audio recorded, transcribed phonetically and analyzed with Percentage Phonemes Correct (PPC) and Percentage of Words Correct (PWC). An analysis of speech error patterns of substitutions of phonemes, reduction of consonant clusters and word structural deviations was conducted. The data recorded from the children were divided and analyzed in four semi-annual intervals and two annual intervals.

The result shows a clear developmental trend with children in the older age group having a higher PPC and PWC than the younger children. Significant differences were found between the groups in annual intervals. Significant differences could only be demonstrated between the youngest age group and the other groups at semi-annual intervals. No significant gender differences were observed. Most of the errors of individual phonemes and consonant clusters among children in all age groups were distortions rather than substitutions, but the younger children simplified consonant clusters more often.