Conducting a class through sustained L2 use is a concept which provides for a major block of classroom time without oral L1 (first language) intervention. During this period, oral L2 is proposed for exclusive use to support goals for developing oral communicative skills. Frequent shifts by the teacher between L1 and L2 are seen to restrict opportunity for uninterrupted L2 listening,1 a phenomenon hypothesized to carry over to student oral production also, as it influences learners to disregard L2 when communicating in the classroom. The nature of grammar learning is complex and under considerable debate. It is not clear how much learners need to be told about grammar nor how much practice they require. If the grammar presentation is highly detailed, especially on the beginning level, Li is likely to be used, since its complexity defies comprehension in L2. It is likewise apt to be done in L1 if it requires students to verbalize rules, a questionable practice, since few students, according to Sharwood Smith, seem to be able to do it. If, on the other hand, the explanation is limited to a degree of explicitness which serves to introduce the grammar point, followed by induction-inducing practice, then communication might well be in L2. A problem encountered in literature on grammar teaching is the absence of clear identification of the level of students being taught. A specialized context involving learners who have little or no difficulty communicating in L2 but who would profit by instruction on refining their grammar skill must not be confused with students in developmental stages of communication. Much of the literature assumes an audience of learners presumed proficient in communication; hence it need not address the question of which language, L1 or L2, will be the vehicle for explanation.2 In such a situation, an L1/L2 mixture may be acceptable, since the learners can receive and discuss information in either language. Such a scenario has no resemblance to that of schools in which massive numbers of students studying Spanish as a second language, including many in advanced courses, are struggling to learn to communicate in Spanish. It is this scenario in which one must decide which language, Li or L2, shall be the languag of instruction. In order to make this decision, one must attend to identifying instructional goals which, for many teachers, will be directed toward developing commonly sought after communication skills, with considerable emphasis on listening and speaking. In conjunction with goal setting, it is crucial to deliberate on instructional processes, vis-avis the language of instruction, to provide for congruence between goals and processes. A prime issue affecting these decisions is how much oral L2 use contributes to or interf res with goal attainment. Experimental evidence is minimal, especially in terms of L2 use in which caretaker speech and other psychological variables are built into the design. However, results of two studies by Seliger suggest a general guideline to the effect that using the target language as a tool for social i t raction affects the rate of second language and the quality of second language acquisition (262). Social interaction includes a variety of communicative situations in which genuine talk takes place. Information giving, a part of this process, could encompass grammar explanation. Teachers, through practical experience, know what works in including grammar explanation in L2. Commonly used techniques are reflected in the concept of comprehensible input which utilizes caretaker speech in the form of linguistic supports (e.g., short utterances, simple vocabulary and syntax, repetitions) and extralinguistic supports (e.g., motor activity, use of visuals) [Kalivoda]. Sharwood Smith (54), in his Type C gramar manifestations, refers to the need for b ief, indirect 'clues' as facilitating techniques. Rutherford (235) adds other possibilities such as the use of a contrast with a related structure or with selected ungram-