We use the word "wish" with past tense verbs to express regret about present situations, such as "I wish I knew the answer" or "I wish I was taller." We use "wish" with the past perfect tense to talk about regrets in the past, like "I wish I had known you then." The phrase "if only" can be used in a more emphatic way to express regret, taking the same verb forms as when using "wish," such as "If only I had more money!" or "If only you were here!"

2. We use wish with past Tenses 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 hollyday with you! If only you were here!(but you´re not) If only the sun would come out! If only I ´d listened to you!(but i didn´t)