find the mistake

Find the mistakes in each of the following sentences, and then write them correctly:
1- Strength as he was, he couldn’t work.
2- However weak he was, he couldn’t work.
3- He was hungry. Although, he refused to eat.
4- Although he wrote well, he got high marks.
5- He refused to eat even although he was hungry.
6- I’m going to buy this shirt even unless it is too large.
7- He was punished because of his bad behave.
8- He was punished because of behaving bad.
9- He is young, but weak.
10- The family went on a flight among the fields.
11- I beated my cousin at tennis table.
12- The boat takes 5 minutes cross the river.
13- Despite his bad write, he got high marks.
14- In spite his writing badly, he got high marks.
15- While wait at the railway station, I saw some tourists.
16- Bad as he wrote, he got high marks.
17- What he would do if he practiced well?
18- What would have been happened if you had met him?
19- Unless you study hard, you will get high marks.
20- Unless it had been so cold yesterday, I would have done swimming.
21- Having studied hard, I had gone swimming.
22- No sooner I had visited Ahmed than it began to rain.
23- Scarcely had I studied hard than Ali came.
24- I went to bed after I have revised my lessons.
25- I won’t leave until you had come