Isn't it really a mistake to say either; "I am going to go shopping or I am going shopping"

"I am going to go to the cinema"

"I am going to the cinema"

My teacher told me that 'I am going to go to ..... is a mistake but I trust native speakers only.Emotion: smile
"I am going to go ..." is not a mistake. It is an example of the simple future using "going to"

Next week I am going to go to the cinema.

When using "going to" many people leave out the verb if it is "to go".

Next week I am going to the cinema.

You can see this "short cut with "come" as well.

I am going to come home on Monday evening. = I am coming home on Monday evening.

These sentences are the same as the present progressive for future use but may also be used for intentions as well as personal arrangements.
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 LouiseT's reply was promoted to an answer.
No, Robin I won't she said that it is a mistake.
Thank you.
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