It's usually dry here at this time of the year. It (not/rain) much​

It doesn't rain much ⠀

здесь нужна отрицательная форма present simple.⠀⠀⠀ ⠀⠀

his hen can fly. - his hen can't fly.

his pig has got a hat. - his pig hasn't got a hat.

his rabbit is grey. -  his rabbit isn't grey.

if you have a best friend you can always rely on him. if you have trouble, he will always be there and always help.