Kedua bentuk ini digunakan untuk menyatakan masa depan, tetapi fungsinya berbeda.
- will-future → keputusan spontan, prediksi, janji, asumsi
- going to-future → rencana yang sudah diputuskan sebelumnya
Time Diagram

Past ----------- Now ----------- Future
│
│ decision now
▼
will + verb
Penjelasan:
- Keputusan dibuat saat berbicara
- Digunakan untuk keputusan spontan
Contoh:
I will help you.
I will call you later.
Diagram for Going-to Future
Past ----------- Now ----------- Future
▲
│ plan already made
│
│
▼
going to + verb
Penjelasan:
- Rencana sudah dibuat sebelum berbicara
- Hanya menyatakan bahwa rencana tersebut akan terjadi di masa depan
Contoh:
I am going to visit my friend tomorrow.
They are going to travel next week.
Comparison Diagram
Past ----------- Now ----------- Future
Plan before speaking → going to
Decision at speaking → will
Quick Comparison
| Future Form | Function | Example |
|---|---|---|
| will-future | spontaneous decision | I will open the window. |
| will-future | promise / prediction | I will call you later. |
| going to-future | planned action | I am going to study tonight. |
| going to-future | prediction with evidence | Look at the sky. It is going to rain. |