This study aims to investigate the perception and production of the English /ɪ/–/iː/ vowel contrast by Cypriot Greek speakers of English as a second language (L2). The participants completed a classification test in which they classified the L2 vowels in terms of their first language (L1) categories, a discrimination test in which they distinguished the members of the vowel contrast, and a production test in which they produced the target vowels. The results showed that they classified both L2 /ɪ/–/iː/ mostly in terms of L1 /i/, which denotes the formation of a completely overlapping contrast according to the theoretical framework of the Universal Perceptual Model (UPM), and that they could hardly distinguish the vowel pair. In addition, their productions deviated in most acoustic parameters from the corresponding productions of English controls. The findings suggest that /ɪ/–/iː/ may carry a universal marker of difficulty for speakers with L1s that do not possess this contrast. This distinction is difficult even for experienced L2 speakers probably because they had never been exposed to naturalistic L2 stimuli and they do not use the L2 that much in their daily life. Finally, the study verifies UPM’s predictions about the discriminability of the contrast and extends the model’s implications to speech production; when an L2 vowel contrast is perceived as completely overlapping, speakers activate a (near-) unified interlinguistic exemplar in their vowel space, which represents both L2 vowels. In addition, Llompart and Reinisch [ 39 ] reported that English /ɪ/–/iː/ was an easy contrast for German speakers as it noted robust perception and better differentiation during production compared to /ɛ/–/æ/. Speech perception is linked to speech production and, therefore, any perceptual deficits are expected to also appear in production. Several psycholinguistic theories attempt to define this link. The motor theory [ 40 , 41 ] suggests that speech perception occurs by detecting intended vocal tract gestures rather than spoken speech. These gestures act as motor commands, providing certain instructions to the articulators. The participants were instructed to sit in front of the monitor and listen to the stimuli through the PC loudspeakers. Then, they were asked to click on the script label that was acoustically the most similar exemplar to the vowel they heard. The labels included the Greek orthographic representation of the 5 CG vowels, namely, “ι”, “ε”, “α”, “ο”, and “ου”. This is because Greek is orthographically transparent and vowels can be reliably presented using orthography, as seen in [ 54 ]. The speakers classified a total number of The participants listened through the headphones to a triad of vowels from the PC loudspeakers and were asked to choose whether the middle vowel (X) was the same as the first (A) or the second vowel (B) by clicking on the appropriate label. Each vowel pair appeared in four possible configurations, namely, AAB, ABB, BBA, and BAA, and they discriminated a total number of 48 items (4 trials × 3 repetitions × 2 voices × 1 contrast + 24 filler words); we used tokens from two out of three speakers in this test. The X token was always acoustically different from the A and B tokens to avoid a solely auditory decision. The interstimulus interval was 1 s and the intertrial interval 500 m.s. The end of the vowel (V) and the beginning of the noise of the second consonant /d/ indicated the vowel’s last point. The vowel formants were measured at their midpoint (50%). The vowel durations were extracted manually through the labeling of the initial and final points of each vowel token. The duration of the vowels was estimated from the measurement of the interval between the starting and ending point of the vocalic part. The normalization of F1 and F2 was produced using the Lobanov method in R ( vowels package; [ 60 ]). 4.2. Results The results of the production test indicated that English /iː/ of CG speakers was acoustically close to the same vowel of English speakers. In contrast, English /ɪ/ of CG speakers was acoustically between /iː/ and /ɪ/ of English speakers. Furthermore, there was an important overlap between the two English vowels produced by CG speakers. In addition, CG speakers produced the English vowels with similar durations to native English speakers. Figure 3 and Figure 4 present the F1 × F2 and duration of English /ɪ/ and /iː/ as produced by CG and English (RP) speakers. Figure 3 F1 × F2 of English /ɪ/ and /iː/ as produced by CG and RP speakers. Figure 4 Duration of English /ɪ/ and /iː/ as produced by CG and RP speakers. We fitted Bayesian regression models in R to analyze the production data. As Spanish and CG have a similar vowel system, perhaps, the learning of this contrast by the participants of this study falls within these developmental stages. Finally, in the lens of UPM’s framework, L2 English /ɪ/ and /iː/ can be characterized as disoriented since they are not acoustically close to the productions of native speakers. Several factors determine the orientation such as L1–L2 use, exposure to the L2, phonetic training, etc. The results of this study allow for drawing some general conclusions about the perception–production relationship. This relationship is reflected in the following way. As /ɪ/ and /iː/ comprise two distinct categories in English, one would expect that their main acoustic parameters would maintain a consistent distance from each other in order to be produced distinctly. While this is the case for native /ɪ/ and /iː/, L2 /ɪ/ and /iː/ acoustically overlap in terms of F1 and, in general, their acoustic spectral distance is smaller compared to the corresponding distance of native productions. This practically means that the members of this completely overlapping contrast, which is the most difficult according to UPM, will hardly be produced with native or near-native properties; they may be produced with similar acoustic properties.