language (some similarities to first language acquisition have been noted as well). When second language speakers "monitor", when they focus on form, this "natural order" is disturbed. The appearance of child-like errors in Monitor-free conditions is hypothesized to be a manifestation of the acquired system operating in isolation, or with little influence of the Monitor.

Current research in the "morpheme studies" supports the hypothesis that second language performers utilize the conscious grammar extensively only when they have to do extreme "discrete-point" grammar tests, test that test knowledge of rules and vocabulary in isolation.

Also included in Chapter 4 is a response to some criticisms of the morpheme studies. Material in Chapter 4 was previously published in Gingras (Krashen, 1978b) and in a paper appearing in On TESOL '77 (Krashen, 1977a).

The Role of the First Language

Chapter 5 deals with so-called first language "interference". It attempts to provide some empirical data for a position first held by Newmark (1966): "interference" is not the first language "getting in the way" of second language skills. Rather, it is the result of the performer "falling back" on old knowledge when he or she has not yet

Fig. 2. First language influence in second language performance.

acquired enough of the second language. In terms of the Monitor performance model, interference is the result of the use of the first language as an utterance initiator: first language competence may replace acquired second language competence in the performance model, as in Fig. 2.

From the data we have so far, this hypothesis correctly predicts that those aspects of syntax that tend to be acquired are also those that show first-language-influenced errors in second language performance.

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