Grammar instruction may enable learners to progress more rapidly along the natural order of acquisition, but its effects may not last without continued practice. Studies found that gains from instruction dropped after 5-6 months unless the grammar structures continued to be used. The effects of different types of formal instruction, like focus on forms versus focus on form, implicit versus explicit instruction, and various corrective feedback options are investigated to determine the most effective methodological approaches. Individual learner differences like learning style, language aptitude, working memory, motivation, and anxiety can also influence how well learners respond to different types of grammar instruction.