A common question is whether 'If I was ...' or 'If I were ...' is correct. The answer is both are correct - depending on the context. 'If I was ...' is often incorrectly used in the unreal conditional, even by native speakers. However, 'If I was ...' is used correctly when 'if' is used to mean 'in the case that ...'. Confused? That's not surprising! It's a confusing issue. Here is an explanation.
If I Were ... Unreal / 2nd Conditional
The third conditional, or past unreal conditional is formed in the following manner:
If + Subject + Simple Past + Objects, Subject + Would + Verb + Objects
If I had more time, I would take up a new hobby.
If Jane moved to New York, she would get an apartment in Brooklyn.
Remember that it is also possible to end the sentence with an 'if' clause. In that case, do not use a comma to separate the two clauses.
Subject + Would + Verb + Objects If + Subject + Simple Past + Objects
The school would hire more teachers if the district voted for a tax increase.
The economy would improve if the people paid less for health insurance.
The problem is the verb 'be'. In the case of the verb 'be', the unreal or imaginary conditional still takes the conjunctive form of the verb 'were' for all subjects. In other words, in the 2nd conditional use 'were' for I, he, she, and it, as well as other subjects.
If Susan were the director, she would invest in new marketing strategies.
I would invest in the stock market if I were a rich man.
In these examples, the subject is not in the position that is imagined. The conjugation of the verb 'be' as 'were' indicates that these are imaginary situations.
You may have often heard people use 'If I was ...' in the same sense. The fact is that native speakers use the incorrect form so frequently that it is becoming standard usage. It's interesting to note that Cambridge University accepts 'If I was ...' for the unreal conditional on their English learning test series whereas ETS (English Testing Service) does not. This is a case of descriptive grammar (how the language is used) winning out over prescriptive grammar (how the language should be used). It certainly causes many headaches for English learners!
If I was ... - Correct Usage
There is a case in which 'If I was ...' (or 'If she / he / it was...') is correct. This form is used to indicate an action that occurred in the past if a given situation arose. In this case, the meaning is similar to 'when'. Notice how this usage refers to a past situation that was true in a specific circumstance, rather than referring to an imaginary situation in the present.
If + Subject + Simple Past + Objects, Subject + Simple Past + Objects
Subject + Simple Past + Objects If + Subject + Simple Past + Objects
I was always in a rush when I was young. If I was in a hurry, I usually forgot my lunch.
She visited Tom if she was in New York when she lived in the United States.
When I was in a hurry, I always forgot my lunch.
Jennifer used to live in the United States. She visited Tom if she was in New York.
In this case, 'if' is acting as a time clause to discuss what happened in a certain situation. Compare this usage to the conditional 0, which uses the simple present in both clauses.
If he comes to town, we go out for lunch. = When he comes to town, we go out for lunch.
If I was available, we spent some time chatting. = When I was available (in the past), we spent some time chatting.
To improve your understanding of conditionals, this conditional forms page reviews each of the four forms in detail. To practice conditional form structure, this real and unreal conditional form worksheet provides a quick review and practice exercises, the past conditional worksheet focuses on using the form in the past. Teachers can use this guide on how to teach conditionals, as well as this conditional forms lesson plan to introduce and practice the first and second conditional forms in class.