I wish I knew ... (wishes and regrets) (B1 Grammar)

Use wish + the past form to talk about a now situation you'd like to be different but can't change. The past form here doesn't mean the past, it signals "this isn't real".

wish + the past form, about now

• I wish I had a car. (I don't have one now)
• I wish I lived in Paris. (I don't live there)
• She wishes she knew the answer. (she doesn't)
• Not "I wish I have more time." — say "I wish I had more time.". After wish, use the past form (had) for a now situation you can't change.
• Try it: My flat is tiny. I ___ a bigger place. (wish I had / wish I have / wish I will have) Answer: wish I had — For a now situation you can't change, use wish + the past form: I wish I had a bigger place. "Wish I have" uses the present, and "wish I will have" uses will, neither of which signals the wish.

wish I were (for everyone)

A wish works like the second conditional: with the verb be you can use were for everyone, including I, he, she and it. Both forms are real — I wish I was is completely normal in everyday speech, and I wish I were sounds more careful, so it's the safer choice in writing and in exams. Learn were, and expect to hear was.

• I wish I were taller.
• He wishes he were more confident.
• I wish I were you.
• Not "I wish I am taller." — say "I wish I were taller.". A wish about now needs a past form — were (or was in relaxed speech). What never works after wish is the present: not "I wish I am".
• Try it: It's pouring and gray. I ___ sunny today. (wish it were / wish it is / wish it will be) Answer: wish it were — In a wish, the verb be is were for everyone, including it: I wish it were sunny. "Wish it is" uses the present, and "wish it will be" uses will, but a wish about now takes were.

Something already done: step back one more

The wishes above are about now. For something already finished that you regret, step the verb back one more: wish + had + the past participle. Compare: I wish I studied art is about now, and I wish I had studied art is about a choice you already made.

• "I sold my car." → I wish I hadn't sold it. (it's already gone)
• "I said that." → I wish I hadn't said that.
• "I studied business." → I wish I had studied art.
• Not "I wish I didn't sell my car last month." — say "I wish I hadn't sold my car last month.". Last month is finished, so the wish goes one step further back: hadn't sold, not didn't sell.
• Try it: I ate the whole cake last night and now I feel terrible. I ___ so much. (wish I hadn't eaten / wish I didn't eat / wish I don't eat) Answer: wish I hadn't eaten — Last night is finished, so the wish steps back to had + the past participle: I wish I hadn't eaten so much. "Didn't eat" would be about now, and "I wish I don't eat" is never possible — a wish does not take the plain present.

no will after wish

Never use will after wish. A wish is about a now situation you can't change, so it takes the past form, not will. "I wish I will ..." is always wrong; say "I wish I had ..." or "I wish I knew ..." instead.

• I wish I knew the answer. (NOT I wish I will know)
• I wish I had more time. (NOT I wish I will have)
• She wishes she understood it. (NOT she wishes she will understand)
• Not "I wish I will know more about it." — say "I wish I knew more about it.". Don't put will after wish. Use the past form (knew) for a wish about now.
• Try it: Which one is right? (I wish I knew more about it. / I wish I will know more about it. / I wish I know more about it.) Answer: I wish I knew more about it. — A wish about now takes the past form: I wish I knew. "Will know" puts will after wish (which doesn't work for a present wish), and "know" is the plain present, which doesn't signal the wish.