Pronunciation plays a vital role in creating a language acceptable to all. This is also true in the case of Sri Lankan English (hereafter SLE). This study concentrates mainly on the phonological features of non-standard SLE, identified mainly by deviations in pronunciation of a few vowels and consonants. The objective of this paper is to analyze the terms characterized as non-standard by using Muysken's theory on Code Mixing. The proposed analysis will categorize elements into insertion and congruent lexicalization strategies. The study will analyze recorded speech of 20 urban bilinguals to obtain data. Self-assessment questionnaires will be used to determine attitudes towards phonologically marked items. Results will reveal that terms which are phonologically marked as non-standard. These phonologically marked items identified as Sinhalizations show more affinity to Sinhala phonology and are based on the speaker's first language. They are products of a grammaticalisation process.