Step 1 of TPRS is “establish meaning” to show what a word/phrase means in the target language (TL) before using it to co-create a story. The most efficient and effective way to do this is by using a native language (L1) common to all students (e.g. “fēlēs means cat“). In TPRS, we write the TL on the board, underline it, then write the L1 below in a different color. We refer to this throughout class by pointing and pausing.
Establishing meaning is also Step 1 for anyone providing comprehensible input (CI), regardless of the method or strategy.
If this step doesn’t occur, teachers are providing input (I) that might not be comprehensible (C). Although there’s some role that noise in the input plays (Incomprehensible Input?), it’s clear that acquisition doesn’t happen with high levels of that noise. This is why no one—NO ONE—disputes that CI is necessary; it’s the sine qua non of acquisition, which is why establishing meaning is so important.
Still, there’s been confusion over establishing meaning, and that confusion has to do with purpose…