Can you hear that? Our neighbours
(have) an argument again.

Yes, I can hear that. The sentence is incomplete as the verb 'have' is in the wrong form. It should be 'are having' instead of 'have'.

Here's the step-by-step explanation:

1. The word 'neighbours' is a plural noun, so we need to use the plural form of the verb 'to have', which is 'are having'.

2. The word 'again' suggests that this is not the first time the neighbors are having an argument. Therefore, it is an ongoing action happening in the present.

3. To form the present continuous tense, we use the auxiliary verb 'are' followed by the present participle form of the main verb. In this case, the present participle form of 'have' is 'having'.

4. So, the correct sentence would be: "Can you hear that? Our neighbors are having an argument again."

Now the sentence conveys that the neighbors are currently in the middle of an argument, and it's not the first time this has happened.