In case (If) I feel sick, I will take medicine.

[abo.omar]

In case I feel sick, I will take medicine.
Does this sentence mean I will take some medicine now because I might feel sick?

If I feel sick, I will take medicine.
Does this sentence mean I will not take not any medicine now unless I feel sick?

 

[jutfrank]

Where did you see or hear these sentences? If you made them up yourself, you must tell us.

 

[abo.omar]

Where did you see or hear these sentences? If you made them up yourself, you must tell us.

I am trying to differentiate between if and in case.
I saw this sentence in a non native book ," In case I feel sick, I will take medicine."
then I found this one on the BBC learning English site.

• [FONT=&quot]I'll fill up the car with petrol in case you need to go to Brighton. ( = I'll fill up [/FONT][FONT=&quot]now[/FONT][FONT=&quot], because you [/FONT][FONT=&quot]might[/FONT][FONT=&quot] need it later.)[/FONT][FONT=&quot][/FONT]
• [FONT=&quot]I'll fill up the car with petrol if you need to go to Brighton. ( = Let me know if you need to go to Brighton and then I'll fill up with petrol.)[/FONT][FONT=&quot][/FONT]
• So I tried to apply BBC explanation on the sentence," In case I feel sick, I will take medicine."

 

[Tarheel]

Filling the tank with gas (petrol) is quite different from taking medicine in case you get sick. Those are two very different things. In the one case we're putting fuel in the car so it will take us places. In the other case we're taking medicine in anticipation of getting sick.

We wouldn't normally bother to mention the reason for putting fuel in the car. (Going to Brighton might be an exception.) As for taking medicine in case you get sick, why would you do that?

 

[abo.omar]

1-In case I feel sick, I will take medicine.
2-If I feel sick, I will take medicine.
So here there is no difference between if and in case. They give the same meaning. I will take the medicine after I feel sick. Am I right?

 

[jutfrank]

If I feel sick, I will take medicine.
Does this sentence mean I will not take not any medicine now unless I feel sick?

This speaker of this sentence is probably talking about the future. If a feeling of sickness comes in the future, I will take some medicine to make myself better. Taking the medicine is a curative measure.

In case I feel sick, I will take medicine.
Does this sentence mean I will take some medicine now because I might feel sick?

This is a poor example sentence. Let me give you another one:

I'm going to take some medicine now in case I feel sick.

The speaker here intends to take the medicine now in order to prevent the feeling of sickness coming in the future. Taking the medicine is a preventative measure.

 

[Tarheel]

We wouldn't normally take medicine as a preventive. There are some exceptions to that, however. For example, people take dramamine to prevent motion sickness.