
If / In case
A conditioned action vs. a precaution
Adverbs for urgent conditions: Do X because Y might happen.
A Conditioned Action vs. a Prepared Action
| ACTION | CONDITION | PRECAUTION | URGENT CONDITION |
|---|---|---|---|
Do this action |
if this happens. (at this moment) |
Do this action (before) |
because X might happen. (emergency) |
Use the batteries and bottled water … |
if there is an earthquake. |
Keep some extra batteries and bottled water on hand... |
in case there is an earthquake. |
Use the fire extinguisher … |
if there is a kitchen fire. |
Buy a fire extinguisher … |
in the event (that) there is a kitchen fire. |
Use the first-aid kit … |
if you cut yourself. |
Have a first-aid kit on hand … |
should you cut yourself. |
on hand – easily available; stored
See If - Statements
Precaution Expressions
| PRECAUTION | URGENT SITUATION |
|---|---|
Do this action in preparation for a possible urgent situation. |
This is the urgent situation (emergency, urgent situation, or a predictable situation) |
Keep your cell phone charged … |
in the event (that) you need to use it. |
Carry your cell phone … |
in case you need to call me for a ride. |
Write down my phone number … |
should you need to reach me, |
Tense Agreement
| PRESENT PRECAUTION | URGENT SITUATION | PAST PRECAUTION | URGENT SITUATION |
|---|---|---|---|
Use present, present progressive or future tense in the precaution clause. |
Use present tense for the urgent-situation clause |
Use past tense for habitual precautions in the past, especially with used to or would. |
Use past tense in the clause with the urgent situation. |
We store emergencies supplies nearby … |
in the event (that) an accident occurs. |
We would keep emergencies supplies nearby … |
in the event (that) an accident occurred. (past habit) |
The men keep a canary with them in the coal mines … |
in case the air turns bad. (present habit) |
The men kept a canary with them in the coal mines … |
in case the air turned bad. (past habit) |
I will carry an umbrella in my car trunk … |
in case it rains. (Do not use future.) |
I used to carry an umbrella in my car trunk … |
in case it rained. (past habit) |
Clause Order – commas
| INITIAL POSITION | MID-POSITON |
|---|---|
Use a comma when placing the conjunction and its clause at the beginning of the sentence. |
Use no comma when the conjunction is between the two clauses. |
In the event (that) you need to reach me, carry your cell phone. |
Carry your cell phone in the event you need me. |
In case you need to reach me, carry your cell phone. |
Carry your cell phone in case you need me. |
Should you need to reach me, carry your cell phone. |
Carry your cell phone should you need me. |
Common Mistakes
| ERROR | FIX |
|---|---|
Call me in case you need help. |
Call me if you need help. (Call me at the moment you need help, not before.)
|
Let's hide in case he comes in. |
Let's hide if he comes in. (Hide at the moment he comes in, not before.) |
He has left his car keys with the neighbor in his in case someone needs to move his car. |
He left his car keys with the neighbor in his in case someone needs to move his car. |
Practice 1
In case vs. If – A Road Trip
- Select the word from each menu that best completes the sentence.
- Compare your response to the answer by clicking the "check" button to the right.
Practice 2
Precautions and Alternate Plans
- Select the word from each menu that best completes the sentence. Pay attention to subject-verb agreement.
- Compare your response to the answer by clicking the "check" button to the right.
See If - Statements for more examples of conditional statements.

