Underline one mistake in each sentence. Rewrite the sentences correctly.

Okay, let's correct these sentences one by one: 1. **Original:** I written about 20 emails today! **Mistake:** "written" should be preceded by "have". **Corrected:** I have written about 20 emails today! 2. **Original:** Our cousins have came to stay with us for the weekend. **Mistake:** "came" is the incorrect past participle form. The correct form is "come". **Corrected:** Our cousins have come to stay with us for the weekend. 3. **Original:** The train just has arrived at the station. **Mistake:** The word order is incorrect. "just" should come after "has". **Corrected:** The train has just arrived at the station. 4. **Original:** We're seen that film five times. **Mistake:** "seen" should be preceded by "have". **Corrected:** We've seen that film five times. 5. **Original:** My uncle has spend two weeks in hospital. **Mistake:** "spend" is the base form of the verb. It should be in the past participle form: "spent". **Corrected:** My uncle has spent two weeks in hospital. **Explanation for each correction:** 1. The present perfect tense (have/has + past participle) is used to describe an action that started in the past and continues to the present or whose result is relevant now. Therefore, "written" needs "have" to form the present perfect tense. 2. The past participle of "come" is "come", not "came". This is a common irregular verb mistake. 3. In present perfect constructions using adverbs like "just", the adverb usually goes between the auxiliary verb (has/have) and the past participle. 4. Again, the present perfect tense requires "have" before the past participle "seen". 5. "spend" is an irregular verb. Its past participle form is "spent". **Развёрнутый ответ на русском языке:** В этих предложениях нужно найти и исправить по одной ошибке. Разберём каждое предложение: 1. **Исходное:** I written about 20 emails today! **Ошибка:** Нужно добавить вспомогательный глагол "have" перед "written", так как это Present Perfect. **Исправленное:** I have written about 20 emails today! 2. **Исходное:** Our cousins have came to stay with us for the weekend. **Ошибка:** Неправильная форма причастия прошедшего времени. Правильная форма – "come". **Исправленное:** Our cousins have come to stay with us for the weekend. 3. **Исходное:** The train just has arrived at the station. **Ошибка:** Неправильный порядок слов. "just" должно стоять после "has". **Исправленное:** The train has just arrived at the station. 4. **Исходное:** We're seen that film five times. **Ошибка:** Нужно добавить "have" перед "seen", так как это Present Perfect. **Исправленное:** We've seen that film five times. 5. **Исходное:** My uncle has spend two weeks in hospital. **Ошибка:** Неправильная форма глагола. Нужно использовать форму прошедшего времени "spent". **Исправленное:** My uncle has spent two weeks in hospital.