3 of 3 Grammar changes

Signals to a deep space network

First of all, sorry for the general context of the question but I’m very inexperienced. I hope I'm not breaking the rules.

Simplifying, in the short sci-fi novel I’m writing there’s a super-intelligent alien probe that wants to communicate with us. It can intercept all of our communications leaving the Earth so it chooses to send a signal to the ESTRACK (or one of the other deep space networks).

Let’s say that the probe wants to send a simple “text” message, maybe a “do you copy?”. If it’s starting to learn English, to grease the wheels, how can it do it? What kind of... “format” would the signal have to be received and understood?