Using In Case

We use in case to talk about precautions – things we should do in order to be ready for possible future situations.

• I always carry an umbrella in case it rains.

After in case, we use a present tense to refer to the future.

In case … should

We often use should + infinitive after in case.

• I wrote down her address in case I should forget it.

Should happen to or happened to is also possible after in case with this meaning.

Compare:

• I have bought a bottle of wine in case John comes.
• I have bought a bottle of wine in case John should come.
• have bought a bottle of wine in case John should happen to come.
• I have bought a bottle of wine in case John happened to come.