Task 3. Complete the sentences using I’m going to … / I’m not going to …. Choose from: Complain / learn / run/ say / try / wash not /accept / not eat / not tell For example: This cheese smells horrible. I’m not going to eat it.
I haven’t been trying hard enough. From now on harder.
I have to make a speech tomorrow, but I don’t know what.
‘The car is very dirty.’ ‘I know . It.’
I’ve been offered a job, but it. The pay is too low.​

Sure! Here is a detailed and step-by-step explanation for completing the sentences using "I'm going to" or "I'm not going to":

1. This cheese smells horrible. I’m not going to eat it.
In this sentence, we are talking about the cheese smelling bad and the speaker's decision not to eat it. We use "I'm not going to" because the speaker has made a decision not to do something in the future.

2. I haven't been trying hard enough. From now on, I'm going to try harder.
In this sentence, the speaker admits that they haven't been putting enough effort into something. However, they are determined to change that and have made a decision to try harder in the future. We use "I'm going to" to express a future action or plan.

3. I have to make a speech tomorrow, but I don’t know what to say.
Here, the speaker mentions that they have to give a speech the next day, but they are unsure about the content or what to say. We use "I don't know what to" to express uncertainty or lack of knowledge about a particular action.

4. "The car is very dirty." "I know. I'm going to wash it."
This sentence involves a conversation between two people discussing the dirty state of a car. The speaker acknowledges the dirtiness and states their intention to wash the car. We use "I'm going to" to express a future plan or intention.

5. I've been offered a job, but I'm not going to accept it. The pay is too low.​
In this sentence, the speaker mentions that they have been offered a job, but they have decided not to accept it. The reason stated is that the pay is too low. We use "I'm not going to" to express a future choice or decision not to do something.

I hope this explanation helps you understand how to complete the sentences using "I'm going to" or "I'm not going to" and the reasons behind each choice. Let me know if you have any further questions!