The document discusses the use of the word "wish" to express regret about present and past situations. It notes that we use wish with past tense forms like "knew", "was", and "were" to talk about present regrets. We use wish with the past perfect tense like "had known" to express regrets about the past. Similarly, "could have" followed by a past participle can indicate past regrets. The document also explains that "if only" can be used more emphatically than "I wish" followed by the same verb forms to talk about hypothetical past situations.

2. We use wish with past Tense forms (simple and continuous) to express regrets about present situations. Past Simple  Present I wish I Knew the answer. ( I don't) I wish I was taller. ( I'm not very tall) I wish they were better at sports.( They are not)

5. We use wish with the Past Perfect when we have regrets about the past. Past perfect  Past I wish I had known you then. (But I didn't) Could Have  Past I wish I could have explained. (I wasn't able to)

6. If only can be more emphatic than I wish . The verb forms are the same as the patterns with wish . If only I had more money! (But I haven't) If only I was going on holyday with you! If only you were here! (But you're not) If only the sun would come out! (But it’s cloudy) If only I'd listened to you! (But I didn't)