Correct spelling, explanation: the phrases if I were and if I was both have a common origin and share the same etymology, rooted in the history of the English language. While if I were may have a more formal or traditional connotation due to its historical association with the subjunctive mood, both forms have the same etymological roots and are used in contemporary English, with if I was being more prevalent in casual conversation. In modern English, both if I were and if I was are widely accepted and used.

Definition of if I were:
Phrase, used to introduce a hypothetical or unreal condition in the present or future
If I were the president, I would focus on improving education and healthcare.
If I were to win the lottery, I would buy a house in the mountains and a beachfront property.

Collocations with if I were:
Some most commonly used collocations include:
1. If I were you: this common expression is used to give advice or make a suggestion, implying that the speaker is imagining themselves in the listener’s situation.
If I were you, I would take a break and relax.
2. If I were in your shoes: similar to the previous expression, this collocation is used when considering someone else’s perspective or situation.
If I were in your shoes, I’d probably feel the same way.
3. If I were to guess: this collocation is used when making a hypothetical guess or estimation about something.
If I were to guess, I’d say she’s probably running a bit late.
4. If I were a betting man: this collocation is used to introduce a hypothetical or playful statement about the likelihood of a certain outcome.
If I were a betting man, I’d put my money on the home team winning.

Correct spelling, explanation: the choice between if I was and if I were depends on the context and the type of condition you are expressing. Use if I were when expressing a hypothetical or unreal situation in the present or future. Use if I was when discussing a condition that is a possibility or a reality in the past. In everyday language and informal settings, both forms are often used interchangeably, especially in the past tense. However, in more formal writing or when emphasizing hypothetical or unreal situations, using if I were is considered more traditional and grammatically correct.