In daily life, sometimes we wish something. For example, If you accept me as your boyfriend, I will love you forever. If I’m rich, I will make an orphanage. If I had wings, I will fly into the blue sky, etc. These sentences called conditional sentences, it means that the activities can be done if the condition are fulfilled. Or I can say, it is causality. There are some rules in using conditional sentences, if we put the “if” clause in the beginning of sentences, we will have to use “,” to the next clause. Otherwise, if we put the “if” clause in the end of sentences, we don’t have to use “,” to separate two clauses.





Type of Conditional Sentences



a). Real conditionals (factual / habitual / hypothetical / future possible)



This type used to expressing the situation or activity that can be happened or fulfilled. In other word, what we wished for can be realized in actual life.



Examples :

1. If I have the time, I will go

2. If I become your boyfriend, I will make you happy forever

i). Future time
If + S + present tense, S + will + Verb1
can
may
must



Examples :

1. If I have the money, I will give it to you. (Jika saya punya uangnya, saya akan memberikannya kepada kamu).
2. If you keep driving on this speed, we may arrive at home before 10 p.m. (Jika kamu terus nyetir mobil pada kecepatan ini, kita mungkin tiba di rumah sebelum jam 10 malam).
3. I can pass this subject if I study hard. (Saya dapat lulus mata kuliah ini, jika saya belajar giat).
4. You must bring an umbrella if you don’t want to get wet. (Kamu harus membawa payung, jika kamu tidak ingin basah (kehujanan).



ii). Habitual (kebiasaan/habit)


If + S + verb1, S + verb1



Examples :

1. If Budi has enough time, he usually walks to campus. (Jika Budi punya cukup waktu, dia biasanya jalan kaki ke kampus).
2. I usually watch football on TV every Saturday night if I do not fall asleep. (Saya biasanya nonton sepakbola di TV tiap Sabtu malam jika saya tidak tertidur).
3. If he has money, he always treats us. (Jika dia punya uang, dia selalu mentraktir kita).



iii). Command (perintah)


If + S + verb1, S + verb1



Examples :

1. If you finish with your work, please help me. (Jika kamu selesai dengan pekerjaanmu, tolong bantu saya).
2. Please give me a cigarette if you don’t mind. (Tolong beri saya sepuntung rokok, jika kamu tidak keberatan).
3. If you have time, please meet me in my office. (Jika kamu punya waktu, tolong temui saya di kantor saya).





b). Unreal atau Contrary to Fact Conditionals



Different with real conditional, this type is a contrary from the fact. It means, if the fact positive (affirmative), then the conditional sentences would be negative.



Examples :

1. If the teacher didn’t speak quickly, I could understand better what he is teaching about
2. He could hug me, if he were here. (Dia boleh memeluk saya, jika dia di sini). Fact : he can’t hug me, because, he is not here



i). Unreal conditionals if the facts in simple present tense



If + S + verb2,


S +


would
could
might


+ Verb1



Examples :

1. If the teacher didn’t speak quickly, I could understand better what he is teaching about. (Jika guru itu tidak berbicara dengan cepat, saya dapat memahami dengan lebih baik apa yang dia sedang ajarkan). Fact : the teacher speaks quickly, so that, I can’t understand well what he is teaching about.
2. He could hug me, if he were here. (Dia boleh memeluk saya, jika dia di sini). Fact : he can’t hug me, because, he is not here.
3. If I had a pair of wings, I would fly high. (Jika saya punya sepasang sayap, saya akan terbang tinggi). Fact : I don’t have a pair of wings, I can’t fly.



ii). Unreal conditionals if the facts in simple past tense





If + S + had + verb3,


S +
would
could
might

+ have + verb3

Examples :

1. If Robby had not gone to a movie last night, he would not have met Susan (jika Robby tidak pergi nonton film (di bioskop) tadi malam, dia tidak akan berjumpa dengan Susan). Fact: Robby went to a movie last night, then, he met Susan.
2. If the German football team had played well, it could have beaten the Spanish team (jika team sepak bola Jerman bermain bagus, team itu dapat mengalahkan team Spanyol). Fact: German foot ball team didn’t play well, it couldn’t beat the Spanish team.
3. You could have answered the questions well if you had studied well last night (kamu dapat menjawab soal-soal dengan baik, jika kamu belajar dengan baik tadi malam). Fact: you couldn’t answer the questions well, because, you didn’t study well last night.


source

http://fikarzone.wordpress.com/2011/11/04/tenth-assignment-conditional-sentences/

http://swarabhaskara.com/miscellaneous/conditional-sentences-part-1/

http://swarabhaskara.com/miscellaneous/conditional-sentences-part-2/