In order to comprehend speech, listeners have to combine low-level phonetic information about the incoming auditory signal with higher-order contextual information to make a lexical selection. This requires stable phonological categories and unambiguous representations of words in the mental lexicon. Unlike native speakers, second language (L2) speakers, who perceive nonnative sounds through the prism of their first language (L1), operate with fuzzy phonological categories, which lead to phonologically ambiguous lexical representations (e.g., the words "rock" and "lock" can be confused if phonological representations for /r/ and /l/ are not sufficiently robust). The present study uses the AX discrimination task to establish the degree of sensitivity of L2 listeners to the Russian hard/soft phonological contrast. The same phonological contrasts are then used in the stimuli for the second task--listening comprehension task with word identification--to mark semantic, syntactic, and morphological distinctions in words. The goal of the study is to examine the contributions and relative efficiency of different contextual constraints (semantic, syntactic, and morphological) to the resolution of phonolexical ambiguity in L2 auditory sentence processing. The results suggest that when L2 phonological contrasts present a discriminability problem and create phonolexical ambiguity, L2 listeners rely on morphological constraints for disambiguation of word forms and syntactic constraints for disambiguation of words belonging to different parts of speech to a greater extent than on semantic constraints for disambiguation of nouns in the same form.