Conditional sentences can be used to describe both real and unreal situations. Conditionals express possible real situations in the future and unreal or hypothetical situations in the present and past. The conditional is stated in a dependent clause begining with "if".Because they lend themselves to testing ideas and discussing possibilities, conditionals are somewhat more frequent in speech than in writing.

• If Mark doesn't show up soon, we'll go ahead and start the meeting without him
• If you want to get the authorization, you need to fill out this form

• If I had the authority, I'd tell them to remove the old equipment. (In fact, I don't have the authority.)
• If we reduced the advertising budget, we'd have more money to invest in new equipment. (This is my idea. I don't expect that it will happen.)

• If the equipment hadn't malfunctioned, we would have met our production target. (In fact the equipment malfunctioned.)
• If we had focused more on the customer's needs than on engineering prowess, we might have boosted our sales. (This is just my opinion. We can't go back and change our strategy )