Be going to

The be going to structure can be used in two ways, which may sometimes lead to confusion:

Future

 * as a very commonly used multi-word verb form, in this case, a semi-auxiliary (i.e. it always needs a main verb, in this example, "make") to express future intention - I'm going to make a nice cup of tea.; also with future intention where a prediction is made based on evidence visible to the speaker Look at those clouds, it's going to rain, Look at that lady, she's going to have a baby; a warning You're driving too fast, you're going to kill us all!

Other future uses

 * to predict the future based on evidence in the present (Look at that cloud - we're going to get soaked!);
 * to make predictions about future events that are outside our control (I've spoken to them about it, but they're going to do whatever they want.)

Present progressive

 * as a present progressive - I'm going to the bank - where "going" means "cycling", "walking", "driving", "travelling", etc. used as the progressive form (present participle) of the main verb.

Present perfect progressive

 * as a present perfect progressive - I've been going to the same dentist for years. - where "going" means "visiting", "using", etc. used as the progressive form of the main verb.

Intention - future or past
As well as future plans and intentions (see above) - I'm going to ask my boss for a rise., we often use be going to in the past: I was going to ask my boss for a rise., in this case referring to something which didn't actually happen or take place.