This study aims to investigate how noticing fonns in relevant input presented immediately after output encourages learners of English to take lexical items into their IL systems. Twenty nine university students, classified into 3 proficiency levels, took part in an experiment, in which they worked on guided composition, and then took notes of what fonns they had noticed in looking at relevant input presented immediately after output. The participants were asked to work on the same guided composition in the following week to examine how they retained lexical items from the relevant input. The results are: 1) The output-input process leads advanced learners to retain more lexical items;. 2) The uptake is promoted when: i) the participants analyze a fonn in the relevant input syntactically, and/or ii) the participants perceive a fonn in the model as being in contrast with its cOWlterpart in their own output and realize Wlgrammatical or less appropriate status ofthe latter; and 3) The output-input process helps learners gain lexical knowledge on use