Conjunctions of Purpose Explained: A Step-by-Step Guide

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Your B2 student is practising a job interview role-play. She leans forward earnestly and says, ‘I want to change careers because I can learn new skills.’ You nod, but something feels off. She’s mixing up purpose with reason, using ‘because’ when she means ‘so that I can learn new skills’ — expressing her intention, not explaining her past motivation. This confusion between purpose and result is one of the trickiest areas for learners tackling conjunctions of purpose.

TL;DR

• Conjunctions of purpose express why someone does something, using structures like to, in order to, and so that.
• B2 learners need explicit instruction on register differences between informal to and formal in order to structures.
• Common errors include confusing purpose with result and omitting modal verbs after so that.
• Effective teaching involves meaning-first presentation followed by controlled practice and communicative activities.

What are conjunctions of purpose in English grammar?

Conjunctions of purpose express the intended reason behind an action — they answer the question ‘why?’ by showing what someone hopes to achieve. Unlike result conjunctions that describe what actually happened, purpose conjunctions focus on intention and goals before the action takes place.

At B2 level, students encounter purpose structures constantly in authentic contexts: business presentations (‘We implemented new software in order to increase efficiency’), academic writing (‘Researchers collected data so that they could analyse trends’), and everyday conversation (‘I’m leaving early to avoid the traffic’). The challenge lies not in understanding the meaning — most learners grasp the concept intuitively — but in choosing the right form for the right context.

Your students probably already know to + infinitive from earlier levels. The B2 goal is expanding their range with more formal alternatives and helping them navigate the crucial register distinctions that separate casual speech from professional contexts.

Purpose vs result distinction

The difference between purpose and result creates confusion because both answer ‘why?’ but with opposite time orientations. Purpose looks forward — ‘I study so that I can improve my English’ — while result looks back — ‘I studied, so my English improved’.

Modal verbs provide the clearest signal of intention. Purpose clauses with so that require can, could, will, or would to show the action hasn’t happened yet: ‘She saved money so that she could buy a house.’ Result clauses use simple tenses: ‘She saved money, so she bought a house.’

A student might produce ‘I went to the store because I needed bread’ when they mean ‘I went to the store so that I could get bread.’ The first explains motivation after the fact; the second expresses forward-looking intention. This B2 flipped lesson on conjunctions of purpose uses authentic video to help students spot these distinctions in context before tackling the grammar rules.

Which conjunctions of purpose should B2 learners know?

B2 learners should master four core structures: to + infinitive for informal contexts, in order to + infinitive for formal situations, so that + modal verb for emphasis, and so as to + infinitive as a formal alternative. Each carries different register expectations and usage patterns.

Informal purpose structures

To + infinitive dominates everyday conversation and casual writing. Carmen Lu’s analysis of purpose clause frequency confirms that the to-infinitive is the most common structure to indicate purpose in English grammar. Students use it naturally: ‘I called to check the time’, ‘We stopped to get petrol’, ‘She moved to be closer to work’.

This structure needs no modal verb and works with any subject. The main teaching point is helping students recognise when informality is appropriate — text messages, friendly emails, casual conversations — versus contexts that demand more formal alternatives.

Formal purpose structures

In order to + infinitive signals professional or academic register. You’ll find it in business reports (‘The company restructured in order to reduce costs’), academic papers (‘Participants were interviewed in order to gather qualitative data’), and formal correspondence. The meaning stays identical to simple to, but the tone shifts dramatically.

So that + modal verb emphasises the intended result and works particularly well when the purpose involves another person: ‘I’ll speak slowly so that you can understand’, ‘We’ll send the report early so that they can review it’. The modal choice matters — can/could for ability, will/would for future intention.

In order that + modal appears in very formal texts but sounds archaic in modern usage. Teach it for recognition rather than active use.

Structure	Formality	Context	Example
to + infinitive	Informal	Conversation, casual writing	I left early to avoid traffic
in order to + infinitive	Formal	Business, academic writing	We hired consultants in order to improve efficiency
so that + modal	Neutral/Formal	Emphasis on intended result	I’ll explain slowly so that you can understand
in order that + modal	Very formal	Legal, academic texts	Measures were taken in order that standards could be maintained

What common errors do learners make with purpose clauses?

The three most persistent errors with purpose clauses stem from L1 interference, register confusion, and modal verb omission. Understanding why these errors occur helps you anticipate problems and plan targeted practice activities.

Purpose-result confusion

Students frequently use because when they mean so that, producing sentences like ‘I study English because I can get a better job.’ This happens because many first languages use a single conjunction for both concepts, leading to direct translation errors.

The confusion deepens when students encounter so as a result conjunction (‘I was tired, so I went to bed’) and overgeneralise it to purpose contexts. They might say ‘I went to the gym so I could lose weight’ instead of the correct ‘so that I could lose weight’.

Modal verbs provide the clearest correction path. When students produce purpose-result confusion, drill the pattern ‘so that + subject + modal + base verb’ explicitly. The modal signals future intention, not past explanation.

Modal verb omission

So that clauses need modal verbs, but students often apply simple present patterns from other structures: ‘I’m calling so that you know the time’ instead of ‘so that you will know the time’. This generalisation error occurs because students pattern-match with simpler structures they learned earlier.

Negative forms cause additional confusion. Students produce ‘I left early so that I don’t miss the train’ instead of ‘so that I wouldn’t miss the train’. The modal carries the tense and the negativity — ‘so that I won’t be late’, ‘so that they can’t complain’.

For correction, provide sentence starters with the modal slot empty: ‘I saved money so that I _____ buy a house.’ This focuses attention on the modal choice without overwhelming students with the entire structure.

Error Type	Incorrect Example	Correct Form
Purpose-result confusion	I study because I can improve	I study so that I can improve
Wrong conjunction	I left early so I wouldn’t be late	I left early so that I wouldn’t be late
Modal omission	She speaks slowly so that we understand	She speaks slowly so that we can understand
Wrong tense after so that	I called so that you know	I called so that you would know
Negative placement	I whispered so that they don’t hear	I whispered so that they couldn’t hear

How should teachers introduce conjunctions of purpose?

The most effective teaching sequence moves from meaning recognition through controlled practice to communicative production. Start with authentic video or text that contains natural purpose clauses, let students notice the patterns, then build up their productive control through staged activities.

Meaning-first presentation

Net Languages’ comprehensive purpose clause guide notes that non-finite purpose clauses are more common than finite purpose clauses in everyday English. Use this frequency data to prioritise to and in order to structures in your initial presentation.

Start with video content where speakers naturally explain their intentions. A TED Talk speaker explaining why they changed careers, a documentary subject describing their goals, or an interview where someone outlines their plans all provide rich input. Students hear the structures in context before analysing the grammar rules.

Elicit function before form. After watching, ask ‘Why did she move to London?’ and collect student responses. When they produce purpose language naturally — ‘She wanted to study’, ‘She moved so she could work in finance’ — highlight these contributions on the board. This noticing stage builds awareness without overwhelming students with terminology.

Controlled practice activities

Sentence combination exercises work particularly well for purpose clauses. Give students pairs of simple sentences and ask them to join them using given conjunctions: ‘I’m learning Spanish. I want to travel to South America.’ Students practice the structural transforms while focusing on meaning connections.

Gap-fill activities with multiple options help students choose appropriate register. Provide a business email with blanks: ‘We’re scheduling a meeting _____ discuss the proposal.’ Options include to, in order to, and so that we can. Students must consider context clues about formality level.

Error correction tasks target common mistakes directly. Present sentences with typical errors — ‘I called because you could know the time’ — and have students identify and fix the problems. This addresses the purpose-result confusion explicitly.

Communicative production

Why-chain speaking games push students toward fluent purpose clause production. Partner A states an action: ‘I’m going to the library.’ Partner B asks ‘Why?’ Partner A responds with a purpose clause: ‘So that I can return these books.’ Partner B continues: ‘Why do you need to return them?’ This creates natural recycling opportunities.

Personal goal discussions generate authentic purpose language. Students describe their plans for the next year, their career intentions, or their learning objectives. The communicative pressure encourages natural structure choice based on meaning needs rather than mechanical practice.

Register-appropriate role plays let students practice formality distinctions. A casual conversation between friends versus a presentation to company directors demands different purpose clause choices. Students experience the social implications of their linguistic choices.

Stage	Activity	Time	Focus
Recognition	Video comprehension + noticing task	15 mins	Meaning awareness
Controlled practice	Sentence combination + gap-fills	20 mins	Form accuracy
Semi-controlled	Error correction + guided speaking	15 mins	Form-meaning connection
Communicative	Why-chain game + personal discussions	10 mins	Fluency development

What level should teachers introduce purpose clauses?

Purpose clause complexity increases across CEFR levels, with simple to structures appearing at A2 and the full range including register distinctions developed by B2. Understanding this progression helps you select appropriate structures and avoid overwhelming lower-level students.

Level progression guide

A2 students can handle to + infinitive for basic purposes: ‘I study English to find a job’, ‘We went to see a film’. Keep examples concrete and avoid complex modal choices. The focus is on meaning connection — what someone wants to achieve — rather than formal alternatives.

B1 marks the introduction of in order to as a formal alternative. Students learn to recognise register differences but aren’t expected to produce formal structures fluently. They might encounter in order to in reading texts or listening materials without needing to use it actively in speaking.

B2 brings the full range including so that with modal verbs. Students can now handle the tense relationships in complex sentences and make conscious register choices. They understand when to use informal to in conversation versus formal in order to in presentations.

C1 students refine their register awareness and tackle subtle distinctions. They might explore so as to as a formal alternative to in order to, or understand why in order that appears in legal texts but not in business emails.

Level	Structures	Contexts
A2	to + infinitive	Simple, concrete purposes
B1	to + infinitive, in order to (recognition)	Basic register awareness
B2	Full range: to, in order to, so that + modal	Active register choices
C1-C2	All structures + subtle register distinctions	Professional/academic precision

ESL Brains’ library contains 1,000+ video-based lesson plans covering levels A1 to C2, with roughly 17 new lessons added every month. This B2 flipped lesson on conjunctions of purpose demonstrates how authentic video content can introduce purpose structures naturally, then guide students through controlled practice and communicative activities that mirror real-world usage contexts.

Frequently Asked Questions

What is the difference between to and so that for purpose?

‘To’ + infinitive is informal and doesn’t need a modal verb (I study to improve). ‘So that’ is more formal, requires a modal verb, and emphasises the intended result (I study so that I can improve).

How do you use in order to and in order that correctly?

‘In order to’ + infinitive is formal and used in business/academic contexts (We implemented new software in order to increase efficiency). ‘In order that’ + modal is very formal and rarely used in modern English.

Is so that a conjunction of purpose or result?

‘So that’ expresses purpose when followed by a modal verb showing intention (can, could, will, would). When ‘so that’ describes an actual outcome without a modal, it shows result instead of purpose.

What conjunctions are used to express purpose and intention?

The main purpose conjunctions are ‘to’, ‘in order to’, ‘so as to’, ‘so that’, and ‘in order that’. The choice depends on formality level and whether you use an infinitive or a clause structure.

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Ready to teach conjunctions of purpose with authentic video content? This B2 flipped lesson uses a thought-provoking TED Talk to introduce purpose clauses naturally, then guides students through controlled practice and communicative activities. The 60-minute lesson includes pre-class preparation materials and in-class discussion tasks. Open this lesson.