The aim of this paper is to examine secondary education learners' performance in L2 writing production using the complexity, accuracy, and fluency constructs. Results show that the measures of fluency, accuracy, grammatical and lexical complexity progress in a significant way: fourth grade students outperform first graders in the aforementioned measures. Secondly, fewer correlations between the writing measures used and the general quality of the compositions are found among the older students than among the younger ones, indicating that the correlations change depending on learners' age. Thirdly, 1st year students exhibit a higher ratio of errors, both in general and also by error category, although only two types decrease significantly in 4th year students: syntactic and spelling errors. Lastly, we find that errors tend to develop in a non-linear way.