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English Grammar Guide

Conditionals (Zero + First)

B1 Conditionals (Zero + First)

Section titled “ Conditionals (Zero + First)”

If is English’s favorite word for “what happens when.” If X happens, Y follows. Simple idea. Complicated tense rules — because English loves making conditionals sound like time travel even when you’re just talking about rain.

Before this, know:
Present SimplePast SimpleB1 — Tense System

Conditionals = if-then logic gates

Section titled “Conditionals = if-then logic gates”

Every conditional has two parts:

Part Name Job
If X… if-clause (condition) The trigger — the situation that causes something
…then Y. result clause (consequence) What happens when the trigger fires

Mandarin marks this with 如果…就… (rúguǒ… jiù…):

如果下雨**，就**我不出去。 (Rúguǒ xiàyǔ, jiù wǒ bù chūqù.) If rain, then I not go-out.

Same verb mood in both halves. English? English picks different tenses depending on how real the situation is. That’s the whole game at B1.

flowchart TD
    START["🤔 What kind of conditional?"] --> REAL{"Is it always / generally true?"}
    REAL -->|Yes — fact, law, habit| ZERO["Zero Conditional<br/>if + present → present<br/><em>If you heat ice, it melts</em>"]
    REAL -->|No — specific future possibility| FIRST["First Conditional<br/>if + present → will + base<br/><em>If it rains, I'll stay home</em>"]


    ZERO --> NOTE1["Scientific truths, instructions, habits"]
    FIRST --> NOTE2["Real plans, warnings, predictions you believe could happen"]

Zero conditional: facts of the universe

Section titled “Zero conditional: facts of the universe”

Formula: If + present simple, present simple

If you heat ice, it melts.

Article Noun Verb Adjective Preposition

This isn’t about one specific future. It’s about how the world works. Every time. Scientific law. Kitchen fact. Universal truth.

When to use zero conditional

Section titled “When to use zero conditional”
Use Example
Scientific facts If water reaches 100°C, it boils.
General truths If you don’t sleep, you feel tired.
Instructions / processes If the light turns red, stop the car.
Habits / routines If I have time, I go to the gym.
Automatic results If you press this button, the door opens.

Mandarin equivalent — same tense vibe throughout:

如果你不加盐，汤就没味道。 (Rúguǒ nǐ bù jiā yán, tāng jiù méi wèidào.) If you not add salt, soup then no flavor.

Both halves describe general reality. No “will.” No hypothetical dream world.

Zero Conditional

If + subject + present simple, subject + present simple

Zero conditional — comma optional, meaning not

Section titled “Zero conditional — comma optional, meaning not”
If you will heat ice, it melts.
If you heat ice, it melts.
Zero conditional = present in both clauses. Will doesn't belong — this is a fact, not a future prediction.
If water will reach 100°C, it will boil.
If water reaches 100°C, it boils.
Scientific truth → present + present. Both sides describe what always happens.

First conditional: real future possibilities

Section titled “First conditional: real future possibilities”

Formula: If + present simple, will + base verb

If it rains tomorrow, I ’ll stay home.

Article Noun Verb Adjective Preposition

This is about a specific future that might happen. Rain tomorrow? Maybe. If it does, you’ll stay home. Real possibility, not fantasy.

When to use first conditional

Section titled “When to use first conditional”
Use Example
Future plans dependent on conditions If the meeting finishes early, I’ll call you.
Warnings / threats (real ones) If you touch that, you’ll burn yourself.
Offers / promises If you need help, I’ll come.
Predictions you believe could happen If they win, the city will go crazy.
Negotiations If you lower the price, I’ll buy it.
First Conditional

If + subject + present simple, subject + will + base verb

The tense mismatch that hurts your brain

Section titled “The tense mismatch that hurts your brain”

Look at this again:

If it rains (present) tomorrow, I’ll stay home (will = future).

The if-clause uses present tense but talks about future rain. That feels insane if your L1 is Mandarin — 如果下雨 uses the same verb form, and 就我会待在家 puts future in the result only.

English does this on purpose. The if-clause uses present to show “when/ if this condition is met.” The result clause uses will because the consequence is in the future.

Zero vs. First — same word 'if', different worlds
Zero — always true (present + present)

If you mix blue and yellow, you get green.

→ Chemistry. Every time. Not negotiable.

If I eat too much, I feel sick.

→ Personal biological fact. Happens reliably.

If the battery dies, the phone stops working.

→ How phones work. General truth.

First — might happen (present + will)

If you mix those two chemicals tomorrow, you’ll get an explosion.

→ Specific future experiment. Could happen. Don’t try this at home.

If I eat too much at the party tonight, I’ll feel sick.

→ One specific event tonight. Maybe you won’t overeat.

If the battery dies, I’ll buy a new phone.

→ Future decision contingent on a possible event.

If vs. when: certainty levels

Section titled “If vs. when: certainty levels”
Word Meaning Example
if Maybe yes, maybe no If I see her, I’ll say hi. (I might not see her.)
when Definitely going to happen When I see her, I’ll say hi. (I expect to see her.)
When it rains tomorrow, I'll stay home.
If it rains tomorrow, I'll stay home.
Rain tomorrow is uncertain → if. Use when for things you're sure will occur: When I graduate, I'll travel.

Both work in zero conditional when the event is routine:

When/If I wake up, I check my phone. (happens every day)

Unless = if not

Section titled “Unless = if not”

Unless packs if… not into one word:

I won’t go unless you come. = I won’t go if you don’t come.

Unless you hurry, we ’ll miss the train.

Article Noun Verb Adjective Preposition

Mandarin: 如果不… (rúguǒ bù…) or 除非… (chúfēi…)

除非你来，否则我不去。 (Chúfēi nǐ lái, fǒuzé wǒ bù qù.) Unless you come, otherwise I not go.

Unless you will not help, I can't finish.
Unless you help, I can't finish.
Unless + present (same as if-clause). Don't double-negative with will not.

Clause order: if first or result first?

Section titled “Clause order: if first or result first?”

Both orders work. Comma rules follow normal English:

If-clause first → comma:

If it rains, I’ll stay home.

Result first → usually no comma:

I’ll stay home if it rains.

I ’ll call you if I finish early.

Article Noun Verb Adjective Preposition

Same meaning. Different drama. If-clause first = setup, then punchline.

More first conditional examples

Section titled “More first conditional examples”

Plans

Section titled “Plans”

If the weather is nice, we ’ll have a picnic.

Article Noun Verb Adjective Preposition

Warnings

Section titled “Warnings”

If you don’t wear a seatbelt, you ’ll get injured.

Article Noun Verb Adjective Preposition

Offers

Section titled “Offers”

If you need a ride, I ’ll pick you up.

Article Noun Verb Adjective Preposition

Practice: zero or first?

Section titled “Practice: zero or first?”
If plants will get no water, they die.
If plants get no water, they die.
General fact → zero conditional (present + present). Not a one-time future event.
If I have time tonight, I go to the gym.
If I have time tonight, I 'll go to the gym.
Specific tonight → first conditional. Result needs will.
If you will heat water to 100°C, it will boil.
If you heat water to 100°C, it boils.
Scientific law → zero conditional. Present + present.
When it will rain tomorrow, I'll stay home.
If it rains tomorrow, I'll stay home.
Uncertain future → if + present. No will in the if-clause.

Other result clause options (not just will)

Section titled “Other result clause options (not just will)”

First conditional results can use can, might, should, must instead of will:

Modal Vibe Example
will definite future result If it rains, I**’ll** stay home.
can ability / permission If you finish early, you can leave.
might possible but uncertain If we hurry, we might catch the train.
should expected result If you study, you should pass.
must necessary result If you want entry, you must show ID.

The if-clause stays present simple regardless.

Conditionals — cheat sheet

Zero (facts): If + present, present

First (real future): If + present, will + base

Unless: Unless + present, will + base (= if… not)

When (certain): When + present, will + base

Never (first conditional): If + will ❌

Try this right now

Section titled “Try this right now”

Write two sentences about your week:

  1. One zero conditional habit or fact about yourself
  2. One first conditional plan that depends on something

Say them out loud. If your mouth wants to say “if I will…” — stop. Present in the if-clause. Every time.

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