Is there such thing as a "IsStill" function?

Hello.

No, there is no thing such as a "IsStill" function. However, you can create your own. To do this, you will use the Touched event.

Here is some code:

script.Parent.Touched:connect(function(part)
	
end)

script.Parent.TouchEnded:connect(function(part)
	
end)

Now you must store the parts so that on TouchEnded you can decide which is the part and which isn't.

Now let's make a table, and a function.

Parts = {}

function IsStill(Part)
	return false
end

script.Parent.Touched:connect(function(part)
	
end)

script.Parent.TouchEnded:connect(function(part)
	
end)

Since we made the table, we will store that part on the table, then verify if it isn't there anymore. This way, you can check if the existent part is on the Parts table.

Parts = {}

function IsStill(Part)
	for i=1,#Parts do
		if (Parts[i] == Part) then
			return true
		end
	end
	
	return false
end

script.Parent.Touched:connect(function(part)
	table.insert(Parts, part)
end)

script.Parent.TouchEnded:connect(function(part)
	for i=1,#Parts do
		if Parts[i]==part then
			table.remove(Parts, i)
		end
	end
end)

Hope this helps you out! ~luadotorg