SUMMARY
This paper offers scientific evidences on the influence of IH proposed by S. Krashen. The purposively selected participants (n = 1615) answered the instruments (0.8572 Cronbach Alpha) asynchronously. Morphosyntax adeptness of L2 learners utilizing descriptive statistics such as frequency, percentage, mean and composite mean ranges from slightly adept to highly adept index. Comprehensible Input (CI) such as speaking activities, writing drills, listening and reading text as primary features of IH are categorized into two (production and reception). The empirical investigation has resulted to an additional IH feature such as extension activities, reward system and viewing linguistic activities as contributory elements to the adeptness index. This study is beneficial to L2 learners across the world as it highlights their vocabulary and learning attitude, and age factors towards L2 acquisition to be taken into consideration by EFL educators across the globe even native language educators handling L2 learners. EFL teachers will most likely be able to provide rich linguistic activities considering the new features of IH adaptive to the 21st century learning styles. Notably, the slight occurrence of L1 on processing L2 fluency may also be considered by EFL teachers as a positive language attitude and a prelude to L2 fluency. From the lens of applied linguistics, it is recommended that other sampling techniques may be used to distribute evenly future participants and achieve higher validity and reliability of findings. The reinforced version and evolution of IH offers a research gap for future researchers to better understand 21st century L2 learners due to the dynamism aspect of language.