Reaction Reactor
Meet an expression. See the scenario it belongs in. Then practise it until the reaction is automatic.
Open App →Whole Class
- 1Project the expression and scenario centrally — Reaction Reactor is a whole-class activity where the teacher controls the pace and the class works through the content together.
- 2Use A.R.T. mode (expression first) when teaching specific target vocabulary: present the expression, build understanding, then reveal the scenario as a production test.
- 3Use Keyword Catalyst mode (scenario first) when practising communicative competence: present the scenario, elicit what expression students would use, then reveal the target form.
- 4The 'Tone Challenge' button generates a variation of the same scenario at a different register — formal, casual, or sarcastic — which tests whether students can adapt the expression, not just recall it.
The Teaching Logic Behind Reaction Reactor
Reaction Reactor generates lexical content for teaching expressions, idioms, and functional phrases — the language people actually use to react to things that happen. Each generation produces a named expression, its definition, a modelled example in context, and a linked scenario that demonstrates exactly when a native speaker would use it.
The two modes serve different pedagogical purposes. A.R.T. mode (Authentic Reaction Training) shows the expression first and builds from form to context — suitable when teaching specific target vocabulary. Keyword Catalyst mode reveals the scenario first, prompts student attempts, then shows the expression — suitable when practising the communicative skill of having the right language ready at the right moment.
The optional Tone Challenge layer generates a tonal variant — the same scenario played out in a formal meeting, a casual conversation, or a sarcastic register. This forces students to ask not just 'what expression?' but 'which version of the expression?' — developing pragmatic flexibility rather than single-form recall.
Teachers can also upload their own document (PDF or image) and the app extracts a custom expression deck from it, saved for reuse in later sessions. Reaction Reactor is ideal when you want to train variety in how students react — replacing the same few overused phrases (always 'I like...', always 'I think...') with a wider, more natural range of expressions for the same function.
Why It Works
Chunks and collocations are the primary unit of L2 acquisition
Lewis (1993) argues that language learning is the acquisition of lexical chunks — multi-word units that function as single items. Reaction Reactor targets exactly these chunks: expressions like 'I couldn't believe my eyes' or 'that's a bit rich' are not reducible to their individual words. Teaching them as wholes, in the scenario where they are used, aligns with how native speakers store and retrieve them.
Knowing a word is not the same as knowing when to use it
Kasper & Rose (2002) define pragmatic competence as knowing the conditions under which a linguistic form is appropriate — its social and contextual rules. The scenario component of Reaction Reactor is not optional content; it is the pragmatic contract of each expression: this is the situation where this language does its job.
Pushed output on expressive language requires semantic depth
Swain (1995) argues that comprehensible input alone does not produce native-like output — learners must be pushed to produce language that is both precise and appropriate. The Tone Challenge creates this 'pushed output' condition for expressive language specifically: students cannot use a generic response, they must produce the tonally correct variant.
Step-by-Step in Class
Choose mode and level
Select a CEFR level (A2+ through C1) and a mode — A.R.T. or Keyword Catalyst. A.R.T. reveals the expression first; Keyword Catalyst reveals the scenario first. Choose based on whether the lesson priority is receptive (A.R.T.) or productive (Keyword Catalyst) practice. Optionally, upload a document to extract your own custom expression deck instead of using a built-in one — useful for targeting expressions a student or class overuses.
Work through the content as a class
In A.R.T. mode, read the expression and definition aloud, discuss the example sentence, then reveal the scenario and ask students: 'Is this what you expected?' In Keyword Catalyst mode, read the scenario, take student suggestions, then reveal the target expression and compare it to what students produced.
Add the Tone Challenge (optional)
Trigger the Tone Challenge to generate a tonal variation of the same scenario. Ask: 'Would you use the same expression here? If you changed anything, what and why?' This single question opens a rich discussion about register, context, and politeness.
Drill and rotate
After analysing two or three expressions, run a choral repetition: teacher reads the scenario, class says the expression in unison. Then reverse: teacher says the expression, class constructs a new scenario. This solidifies the form-meaning-context triple that makes an expression genuinely available for spontaneous use.
How to Set It Up for Different Levels
Generates high-frequency social expressions with everyday scenarios — surprise, disagreement, empathy, relief. Definitions are clear and example sentences are in informal but correct English.
B1 learners understand social expressions passively but avoid producing them because they feel formulaic. A.R.T. mode normalises the use of fixed expressions by demonstrating that even native speakers use memorised chunks in predictable situations.
Generates a rich scenario first, elicits student response, then reveals the idiomatic target expression. B2 level idioms are figurative but high-frequency — 'cut corners', 'a mixed bag', 'read between the lines'.
When students attempt to express something in their own words before seeing the target idiom, the moment of revelation — 'oh, there's a single expression for that!' — produces a strong noticing effect that substantially aids retention.
Generates a target expression, scenario, and Tone Challenge variation at a different register. At C1, the expression set includes formally appropriate equivalents: 'I must confess' versus 'I have to be honest' versus 'let me tell you something'.
C1 learners already know many expressions but overuse informal registers in formal contexts and vice versa. The Tone Challenge targets this specific pragmatic weakness: not knowledge of expressions, but knowledge of which expression fits which register.
Ways to Extend the Game
Expression Radar
During a listening or reading activity, students use expressions from Reaction Reactor sessions as 'radar targets' — they note any occurrence of the target expression or its close synonyms. Converts reactive vocabulary into active listening frames.
Scenario Swap
Give each student a target expression from a previous session. They write a new scenario where the same expression fits and swap with a partner. The partner must decide if the expression genuinely fits the new scenario — and explain why or why not.
Register Translation
After the Tone Challenge reveal, students rewrite the formal scenario in casual English and the casual scenario in formal English using the most appropriate tonal variant of the expression. Develops conscious register code-switching.
Three Reactions in 60 Seconds
Teacher reads a scenario aloud; students have 60 seconds to write three different expressions that could fit it at different tones or levels of intensity. The class votes on which is most natural. Trains the breadth of lexical selection rather than recall of a single form.
Pair It With
Act it Out
Act it Out is the production test for Reaction Reactor sessions — when students have learned a set of expressions, the improvised role-play in Act it Out puts them under communicative pressure to use those expressions naturally and in context.
Definition Wizards
Definition Wizards provides a vocabulary depth check for expressions learned in Reaction Reactor — if a student can circumlocute around an expression without using it, they have genuine semantic knowledge of what it means, not just recall of its surface form.
BubbleTalk
BubbleTalk provides multi-perspective discussion on the topic of a Reaction Reactor scenario — after practising the expression, generating speech bubbles on the same situation creates extended productive use of the exact context students have just analysed.