Sentence translation

If it rains tomorrow, the meeting wilL BE put off.
如果明天下雨，会议就会推迟
If it doesn't rain tomorrow, the meeting will not BE put off.
如果明天不下雨，会议就不会推迟
If it didn't rain yesterday, the meeting would NOT HAVE BEEN put off.
如果昨天不下雨，会议就不会推迟
If he helps you, you will make great progress.
如果他帮你，你就会取得很大进步
If he doesn't help you, you will FIND IT difficult to make great progress. /YOU WILL NOT MAKE GREAT PROGRESS.
如果他不帮助你，你就很难取得进步
If he didn't help you, you wouldn't HAVE MADE great progress. (OR ...WOULD NOT ...)
如果他没有帮助你，你就不会取得那么大的进步