1)if the human race does not worry about languages, many of them will disappear soon
2) if the human race did not worry about languages, many of them would disappear soon
3) if the human race had not worried about languages, many of them would have disappeared soon
1) if you improve your English, you will have more job opportunities
2) if you improved your English, you would have more job opportunities
3) if you had improved your English, you would have had more job opportunities
1) I will be able to understand her if she speaks very slowly
2) I would be able to understand her if she spoke very slowly
3) I would have been abe to understand her if she had spoken very slowly
1)If we go to England, we will study English in a language school
2)If we went to England, we would study English in a language school
3)If we had gone to England, we would have studied English in a language school
1)What will you do tomorrow if it is warm and sunny?
2)What would you do tomorrow if it was warm and sunny?
3)What would you have done tomorrow if it had been warm and sunny?