Thirty‐four German high school students learning English as a second language under classroom conditions were observed for a period of eight months. It was found that the students' utterances showed many structural features which are also known to characterize LI and naturalistic L2 acquisition. It thus appears that formal instruction cannot eliminate or suppress those processes which constitute man's natural ability to acquire language(s). In contrast to naturalistic learners, however, the high school students were continuously forced to produce structures for which, developmentally, they were not yet ready. Here, the students used two basic strategies: (a) they followed principles of naturalistic acquisition; (b) they randomly selected any one structure from a finite repertoir