Using Apple Watch Series 4

MaximLtt wrote:

I'm thinking of buying Apple watch, but I can't afford to update my Iphone 6.

If I were you, I'd save the money and use it toward updating your phone rather than spending it on an Apple Watch.

The answer depends on what version of Watch OS you are using.

If it is a watch OS5 yes, if it is OS6 then the answer is no.

You should be able to, but why don't you update both your iPhone and Watch , unless you have an iPhone 6 or earlier. It would be helpful if you give us the complete picture.