If there are no bees, flowers will not be pollinated.
If I am going to help, you need to give me your attention.
If I am to help, you need to give me your full attention.
If you will step this way please.
If you will only try a little harder, you will succeed.
If you won't work harder, then you will continue to fail.
If you are unwilling to work harder, then you will continue to fail.
If I go shopping, I take a cloth bag.
If we went shopping, the store gave us a bag.
Whenever, we go shopping, we walk.
Jack will cut the grass if he has time.
Jack would cut the grass if he had time.
Jack would cut the grass if he would / could / might / had time.
If I moved my pawn forward, then I could take his bishop.
If the second engine hadn't caught fire, the plane could have made an emergency landing.
If the night watchmen had had binoculars, they would have been able to spot the iceberg earlier.
The captain could have steered directly into the iceberg causing less damage.
The Titanic should have had more lifeboats.
If you had fed the dog, she wouldn't be hungry now.
If I had known (that) your dog was aggressive, I wouldn't have offered to feed it.
If I had known (that) your dog was ill, I would have offered to help it.
We wish to go with you. (direct request / demand)
I wish I were home in my country. (a private thought; longing)
I wish I could go with you. (an excuse or an expression of regret)
I wish you would let me pay for dinner. (pretend regret, or upset)
I wish you'd turn that TV off! (low expectation request; anger)
My father wished he had gone to college. (I regret he didn't.)
My father wished that I would go to graduate school. (I did.)
I wish father had understood my appreciation.(I regret he didn't.)
I wish my son understood his grandfather's efforts. (He doesn't.)
I wish my son would understand the importance of hard work. (He might one day.)
If you cook your turkey like this, you will have a tender turkey.
Only if you cook your turkey like this, will you have a delicious dinner.
Unless you cook your turkey like this, you will have a tough turkey.
Cook your turkey like this. Otherwise, you will have a tough turkey.
I don't know if my cell phone will work here.
I don't know whether my cell phone will work here.
I don't know whether my cell phone will work if I use it here.
If I were/was you, I wouldn't get involved.
Were I you, I wouldn't get involved.
Had I known, I would have said something.
Should you see him again, call me immediately.
Keep some extra batteries and bottled water In case there is an earthquake.
Get away from falling objects if there is an earthquake.
I will win this singing contest!
I am determined to win this singing contest!
The judges won't let me sing another song.
The judges were unwilling to let me sing another song.
I would have done better, but my voice cracked.
I hoped that I would do well, but my voice cracked.