This article concerns second language teaching with a format-based method. The followingarticle in this issue concerns foreign language teaching using the same approach. In the presentstudy, the differences between a format-based teaching approach and a standard approach used astreatments in a quasi-experimental, nonequivalent control group design are described in detail.The hypothesis tested is whether the effects of a format-based teaching method and a standardsecond language teaching method differ after two years for children at the age of 6. Results ofMANOVA analysis for repeated measures show that the groups are quite comparable on thedependent variables, with some small differences in development between the two groups.Univariate results reveal that these differences favor children in the experimental group for soundarticulation and favor children in the control group for sound discrimination. The results of thepresent article and those of the following article are discussed in light of broader issuesconcerning the differences between second language and foreign language teaching.