Expressing the Future

Present Simple     Present Continuous
Some verbs that concern events on a definite schedule or timetable are generally used in the Simple Present Tense, but they may give expression of future. These sentences in Present Simple usually contain future words such as to be, open, close, begin, start, end, finish, arrive, come, leave, return.
İngilizce'de bazı fiiller yapı olarak geniş zamanda kullanıldığı halde anlam olarak gelecek zamanı ifade etmektedir. "To be, open, close, begin, start, end, finish, arrive, come, leave, return" gibi fiiler buna örnek verilebilir.

The bus LEAVES Malatya at 11 tonight.

This term BEGINS on Wednesday next week.

Tomorrow IS Friday. (IS=TO BE)

Some sentences that concern a definite plan or arrangement contain expression of future, but those verbs might be used in Present Continuous, and we can understand their future meaning from only context.
İngilizce'de bazı cümleler, anlam olarak gelecek zamanı ifade eder ancak aşağıdaki örneklerde görüldüğü gibi yapı olarak şimdiki zamanda kullanılabilir.

George IS TAKING his TOEFL exam next year.

They can’t play tennis with you tomorrow because they’RE WORKING.

We’RE GOING to the cinema on Friday.
Be Going To Will
1) "Be Going To" can be used while the speaker is making a prediction based on evidence.
"Be Going To" konuşmacı, belirtilere dayanarak gelecekle ilgili tahminde bulunuyorsa kullanılabilir.

There’s a cloud in the sky. It’S GOING TO rain.

2) "Be Going To" can also be used when the speaker already has an intention or plan.
"Be Going To" yapısı konuşmacı bir plana veya niyete sahipse kullanılabilir.

We’RE GOING TO paint our livingroom tomorrow.

John has won the lottery. He says he’S GOING TO go to buy a house in Cambridge.

He has passed KPSS, so he is happy he'S GOING TO be a teacher of English.

1) "Will" can be used when the speaker is making a prediction.
"Will" konuşmacı o an için kestirimde (tahminde) bulunuyorsa kullanılabilir.

Tomorrow WILL BE hot and sunny.

People WILL GO to Mars in the next decade.

2) Or "Will" can also be used when the speaker decides to do something at the time of speaking. He had no previous plan. Spontaneous.
Veya konuşmacı o an için gelecekle ilgili ani bir karar alıyorsa, "Will" kullanabilir.

Hold on. I’LL GET a pencil.

We WILL SEE what we can do to help you.

Maybe we’LL STAY IN and WATCH television.