Facts, rules & zero conditional — Unit 31, Pre-intermediate to Intermediate English
Vocabulary for general truths, rules, and cause-and-result situations.
Reading: Safety First: The Science Laboratory
In a school laboratory, safety rules apply at all times. **If** you leave a chemical container open, it contaminates the air in the room. This is why every experiment must follow strict procedures. **Whenever** a student finishes using a substance, he or she replaces the lid immediately. The rules exist because chemistry works predictably — **if** you mix certain chemicals, a reaction always occurs.
**As long as** students wear protective goggles, the risk of eye injury stays very low. The teacher checks safety equipment at the start of every lesson. **Unless** you wear a lab coat, you are not permitted to handle acids or bases. This rule applies to every student, regardless of experience or age.
**Whenever** the fire alarm sounds, everyone leaves the building in an orderly way. Students never stop to collect their bags — they walk directly to the nearest exit. **If** a student notices a spillage, he or she reports it to the teacher straight away. Delay makes the situation more dangerous, and the teacher deals with it immediately.
**If** the ventilation fan is off, strong fumes build up quickly. The teacher switches the fan on **whenever** practical work begins. **As long as** the fan runs at full power, the air quality stays safe for everyone. **Unless** the equipment is checked weekly, small faults can go unnoticed for months.
At the end of every lesson, students clean their workspaces thoroughly. **Whenever** broken glass appears on the floor, the teacher uses a special dustpan — bare hands are never safe. **If** a student burns a hand on a hot surface, cold running water is the correct first treatment. **As long as** everyone follows these procedures, the laboratory remains a safe and exciting place to learn science.
**Why these rules are written this way**
Students sometimes ask why the safety notices use "**if** X happens, Y happens" rather than "you must" or "you should". The reason is deliberate.
"You must wear goggles" describes a rule made by a person, and a rule made by a person can feel negotiable when nobody is watching. "**If** acid enters the eye, permanent damage occurs" describes what the world does, and the world is not watching either — it simply does it.
**Whenever** a rule is explained as a consequence rather than an instruction, students follow it more reliably. This is not a theory about teenagers; it applies equally to adults.
**As long as** you understand the mechanism, you can also work out what to do in a situation nobody wrote a rule for — and in a laboratory, that situation arrives eventually.
**Unless** you understand why, you are only ever following the rules you happen to remember.
Vocabulary from this unit
| Word / phrase | Meaning | Example |
|---|---|---|
| fact | something always true | It's a fact that ice melts. |
| rule | official instruction | Follow the kitchen rules. |
| result | what happens because of something | The result is clear. |
| cause | the reason | Heat is the cause. |
| automatically | without action | The light turns on automatically. |
| condition | the 'if' part | On one condition: bring a receipt. |
| Word / phrase | Meaning | Example |
|---|---|---|
| as long as | only if | You get a refund as long as you have a receipt. |
| provided that | formal 'if' | Provided that you arrive early, you'll be fine. |
| whenever | every time | Whenever I exercise, I feel better. |
| unless | if not | Unless you check, you can't be sure. |
| in general | usually | In general, shops open at nine. |
| typically | usually | Typically, the process takes a week. |
This is the free sample from this unit. The full unit adds 1 more reading passage, comprehension questions with an answer key, the listening exercises, flashcards for the vocabulary above, and a speaking task — with your progress tracked so the next unit unlocks when you are ready for it.
Common questions
What level is this unit?
Pre-intermediate to Intermediate — roughly CEFR A2–B1. If you are not sure of your level, the course places you with a short diagnostic before you start rather than making you guess.
Do I need to pay to use this?
The reading passage and vocabulary on this page are free to read. The rest of the unit — the remaining passages, the exercises, the listening, the answer key and the progress tracking — is part of the paid General English course.
Is this British or American English?
British English spelling and vocabulary, which is what most learners in Azerbaijan are taught and what IELTS expects, though both are accepted in the exam.