even if he only has the two tips of baby spoon of a new food do I have to wait four days to…

It's really up to you and how comfortable you are with moving to a new food. If food allergies run in your family then I'd recommend waiting. With my daughter we only waited a couple of days in between new foods but I was comfortable with doing so because food allergies are almost non existent in my family.

Yes. Any amount can cause a reaction. So if he had two bites of banana and the next day 6 bites of avocado he could have a reaction to the banana and you wouldn't know which it was.

I'd say wait for NEW foods but if he's already had say strawberries a lot you know he isn't allergic to them then I wouldn't mind trying something new before or after something you know for sure. But only if you're 100% sure

I would wait a week before you try a new food with him so it will give you time to see if he is allergic to it

okay thank you ladies ! @coraanne @thehowtohippie @reaganmommy2015