will, going to or present continuous?

Rules

• Rule 1: going to → plans made before and predictions from evidence

  We use be going to in two cases: 1) You decided before speaking — you have an intention (I've decided, I bought…, I've saved…). 2) You can see evidence now that shows what will happen (dark clouds, a glass at the edge, 1% battery).

  Pattern: am / is / are + going to + base verb

  Example: I've saved enough money. I'm going to buy a telescope.

  Example: Careful! Your ice cream is going to drip on your shirt.

• Rule 2: will → opinions and guesses

  When there is no evidence and you are just giving your opinion, use will. Clues: I think, I'm sure, I bet, maybe, perhaps, probably, I don't think. Note: the negative goes on think: I don't think he'll come.

  Pattern: I think / I'm sure / maybe … + will + base verb

  Example: I'm sure your team will do well.

  Example: I don't think it'll be crowded.

• Rule 3: will → instant decisions, offers, promises, requests

  Use will when you decide at the moment of speaking, offer help, or make a promise. For requests: Will you…? When something refuses to work: won't.

  Pattern: I'll … · I promise I won't … · Will you …? · It won't …

  Example: You look cold. I'll get you a blanket.

  Example: The zipper won't close!

• Rule 4: present continuous → arrangements

  Use the present continuous for plans that are arranged with other people and have a time or place: appointments, meetings, bought tickets. (In American English be going to is also very natural for these plans: *I'm seeing a movie tonight* = *I'm going to see a movie tonight*.)

  Pattern: am / is / are + verb-ing + time (tomorrow, at six…)

  Example: We're visiting the planetarium on Friday.

  Example: What are you doing after school?

• Rule 5: present simple → timetables and the calendar

  Use the present simple for official schedules: trains, planes, classes, movies, calendar days. But don't use it for personal plans: ~~I meet Noah tomorrow.~~

  Pattern: The train leaves … · The lesson starts … · Tomorrow is …

  Example: The documentary starts at 8:30 tonight.

  Example: Our school trip bus returns at five.

Common mistakes

• I meet my cousin tomorrow. → I'm meeting my cousin tomorrow.

  Don't use the present simple for personal plans; an arrangement → present continuous.

• I think it is raining tomorrow. → I think it will rain tomorrow.

  Weather can't be arranged; an opinion → will.

• Wait, I help you! → Wait, I'll help you!

  An instant offer → will.