Should I mix everything up when I revise? — yes for grammar, no for words

The problem

You have heard that you should “mix everything up” to make it stick. So your session looks like an upended drawer: three verbs in the passé composé, eight kitchen words, two sentences in the imparfait, a list of colours. After twenty minutes you no longer know what you were working on; you feel you have brushed past everything and held nothing. You tell yourself you are disorganised.

You are not disorganised; you applied good advice to the wrong material.

What the research found

The advice comes from real studies. Nakata and Suzuki (2019) had 115 Japanese students practise five English grammar structures. One group did the exercises in blocks, one structure after another. Another mixed them from the start. A third began in blocks and mixed more and more. During training, the mixed group made the most errors. A week later, on a grammaticality judgement test, it was the group that remembered best, and the advantage was larger for those who started lowest.

But in the same year, Brunmair and Richter (2019) pooled 59 studies, 238 measurements, on mixing across every type of material. On average, mixing helps (g = 0.42, a medium effect; g measures the gap between two groups in standard-deviation units). For recognising painting styles the effect is strong. For maths problems it is small. For word lists it reverses: g = −0.39, and learning in blocks beats mixing.

The mechanism makes these results fit together. Mixing helps when the task is to tell similar things apart: the passé composé and the imparfait, or two endings that look alike. Seeing the cases side by side forces the brain to notice what separates them, and it is that comparison that stays. A word list asks for no distinction; each word is its own small piece of learning. Mixing it with other piles creates no useful comparison, just load.

Do this today

Take your next session and cut it in two. First half, in a block: ten words from one world, the kitchen or transport, repeated until you can find them on your own. Second half, mixed: five sentences where you must choose between two grammar points you confuse, in an unpredictable order. You will make more mistakes in the second half. That is the price of mixing, and it is what makes it work.

How our lessons use it

The reading activity « Je m’appelle Nadia » (A1) is a block, in the good sense of the word: one story, one world of words, which you read, hide and recall as three details, her name, her city, what she likes on Saturdays. Nothing is mixed, and that is deliberate. Then « Dis-le à ta façon » has you produce three sentences about yourself, and that is where you start choosing for yourself, between what you know and what you want to say. Je m’appelle Nadia (A1)

The honest limit

Nakata and Suzuki measured English grammar in Japanese students, over one week, through grammaticality judgements, not speech. Brunmair and Richter’s meta-analysis draws mostly on laboratories and non-linguistic material; the result for words rests on a small number of studies. “Mixed grammar, blocked words” is a reasonable guide, not a law.

Your questions