This study investigated the morpheme acquisition order of Swedish students in grades 6 and 7, utilizing corpus texts drawn from the Uppsala Learner English Corpus (ULEC). It is an extension of Khor (2012) that focused on students in grades 9 and 12. Previous studies on morpheme acquisition order suggested that there was a natural sequence in acquiring morphemes, regardless of first language (L1). First language influence was said to be minimal or non-existing. Recently, studies have found evidence that L1 transfer is greater than first thought. This study examined three morphemes; articles, the preposition in, and plural form. The results showed that the errors that both groups made were consistent with the errors that were found in Khor (2012). The errors were of the same nature in all age groups, mainly in differences in (1) generic and specific usage of articles in Swedish and English, (2) the generic sense of regular plural nouns, (3) plural form of irregular nouns and nouns of Latin or Greek origin, (4) plural forms of countable and misuse of uncountable nouns, and (5) the usage of prepositions in Swedish and English. Current studies have also generated these results, which points towards strong L1 influence. The different usage and the errors suggest that the first language influence is stronger than first described, and consequently, that it influences the acquisition of morphemes. Therefore, the L1 seems to shape the order in which grammatical morphemes are acquired. Learners in one language group seem to learn the morphemes in a specific order, rather than a fixed universal order.