Mary is so young that she can't make up her own mind about matters.

• Mary is not old enough to make up her own mind about matters.

Although Bill's hand-embroidered picture was expensive, we bought it.

• In spite of the fact that Bill's hand-embroidered picture was expensive, we bought it.

Some teachers will hold classes in places like parks or supermarkets.

• Classes will be held by some teachers in places like parks or supermarkets.

Peter used to go to school late.

• Peter no longer goes to school late.

The last time he wrote to his parents was 2 weeks ago.

• He hasn't written to his parents for 2 weeks.

I'm really excited about the upcoming pottery workshop.

• I'm looking forward to the upcoming pottery workshop.

I think you should read English papers to improve your reading skill.

• If I were you, I would read English papers to improve your reading skill.

Parents must teach their children what to do about rubbish.

• Children must be taught by their parents what to do about rubbish.

Peter doesn't see a fly in his soup, so he doesn't tell the manager.

• If Peter saw a fly in his soup, he would tell the manager.

Maria asked Tom, "Shall we have a test next week?"

• Maria asked Tom if they should have a test next week.