The present continuous tense and the phrase ‘going to’ can overlap at times. Both of them are used to talk about future decisions. The present continuous tense has more possible uses than that, but when used to talk about the future, it does have a different meaning.
Present continuous is, essentially, when the present participle form of a verb – which is usually the one that ends in –ing – is used with a present-tense form of ‘to be’: ‘am’, ‘are’, and ‘is’.
“I am watching television.”
There are a few verbs that cannot be used as a continuous form, which are known as non-continuous. They generally represent things that are not actions that can be seen, such as emotions, desires, or possession. All of those things – loving, wanting, owning – are abstract, while most normal verbs – running, jumping, reading – are concrete actions that you can see someone doing.
The first use of present continuous is to express that an action is happening at the present time, and that it is ongoing.
“She is watering the garden.”
Secondly, it can be used to talk about a bigger project that is in progress. These are usually things that will take a long time to complete, even if they are not being worked on at the time of speaking.
“I am writing a novel.”
It can also be used to talk about a recurring behavior with an adverb like ‘always’ or ‘constantly’, which are placed between the ‘to be’ verb and the present participle. This is almost always used to express irritation at that behavior, and it’s most often used in the third person.
“He’s always changing the subject when I try to talk about my writing.”
Finally, we have the use that overlaps with ‘going to’: actions that will happen in the near future.
“We can’t do that, because you’re visiting your mother this weekend.”
‘Going to’, as mentioned above, means something similar to the last example. It is a future tense, and talks about things that will happen because they have been planned,
“I am going to study pre-law.”
It can also mean things that have been predetermined in another way, such as by fate or because other things are pointing toward it happening.
“It is going to rain tomorrow.”
It does look like an example of a present continuous verb, since ‘going to’ is the present participle of ‘go to’, and it is typically used with a present tense of ‘to be’. It actually can be used as a present continuous verb when the sentence is discussing travelling to another place.
“I am going to London.”
You might notice a difference between the present continuous usage and the normal usage. In the present continuous example, ‘am going to’ is the only verb. The other examples each have another verb: ‘study’, ‘run’, ‘rain’, and ‘end up’. In the other examples, ‘going to’ is a modal or auxiliary verb, which means that it is used to modify other verbs.
There is also a difference between using ‘going to’ and a present continuous verb.
“I am going to get a cat.”
“I am getting a cat.”
The second sentence is about getting a cat and the first sentence places more emphasis on the ‘going to’ part. The first sentence focuses more on the decision to get a cat, while the second focuses more on the act of getting the cat.
To summarize, the present continuous form is used to talk about things that are happening, whether in the moment, over a long period of time, or are recurring. It can also be used to talk about future events. ‘Going to’ modifies other verbs to make them future tense. When talking about future events, a present continuous emphasizes the events while ‘going to’ is more about the decision to make those evens happen.