The phonological system can be described and analyzed on three levels; word, syllable and segment. The non-linear nature of the system enables an analysis from different viewpoints on phonology. LINköpingsUnderSökningen (LINUS) is a phonological test for children between the ages of 3 to 6 years which enables a non-linear analysis. Previous studies at  Linköping University have shown that children with phonological language impairment have phonological deviations on all three levels. Even though there is research involving Swedish-speaking children with expressive phonological impairment, further research is needed due to lacking in sample size and age span of participants. The purpose of this thesis is to compare the expressive phonological ability of children between the ages of 3 to 5 years who have been referred to a speech and language pathologist (SLP) for suspected phonological difficulties with a control group consisting of peers without known difficulties. In the study 10 children participated who were recruited from a speech and language pathologist clinic in a big city in Sweden, and raw data was also used from a previous study on an additional 11 children. Children with language impairment were matched with a control group with children of the same age. The age interval of participating children was between 3 years and 2 months and 4 years and 11 months.  The LINUS test was issued at a speech and language pathologist clinic together with a SLP.  The results showed similar deviations on word, syllable and segment level for both the study group and the control group. However the results of the study group contained a higher amount of deviations. The word and syllable level caused the greatest challenge for both groups. Additionally, both the study group and the control group exhibited deviations in terms of word structure where the most frequent shortcoming was reduction of consonant clusters. To conclude, similar types of deviations occurred in both groups, although the study group had a higher amount of deviations on all levels. For stronger conclusions, a larger sample size and younger participants are needed.