I have never had malaria several times, but the ones I had when I was a kid, I will respond base on my experience after it was confirmed that is malaria.
How do you know when you start to get malaria?
My answer: You feel dizzy, tired most times and lack of hungry for food
How can you tell that it is malaria and not, say, a flu or a cold?
My answer: Through lab diagnosis
Are there any specific symptoms which might even be very subtle so that you are able to differentiate? Or do you recognize it from how it felt when you had malaria as a child?
My answer: As a kid I will like to seat on the sun, sometime vomiting; and sleeping than necessary.
Do you maybe recognize it like you recognize a face or a voice?
My answer: My eyes sometimes change to yellow like color and I become slow in talking.