How would you translate "I will buy something"? I came up with: なにかかいます。
But I'm not sure if this is correct.
Thanks!
In common speech many people say things like:
スーパーで何{なに}か買{か}ってきます。
You can also say「なんか」 instead of 「なにか」 to mean "something" in this case if you like.