## Why does Sorbet think this is `nil`? I just checked that it's not!| sorbet.org
Recall from [Enabling runtime checks](/docs/runtime) that `sorbet-runtime` raises| sorbet.org
This is one of three docs aimed at helping answer common questions about Sorbet:| sorbet.org
> This page describes the syntax of method signatures, or `sig`s. For a complete| sorbet.org
The type `T.untyped` represents a type that Sorbet has no specific knowledge| sorbet.org
```ruby| sorbet.org
| sorbet.org
Sorbet provides the most value when it has a wealth of programmer-supplied| sorbet.org
As we've mentioned before, Sorbet is a [gradual](/docs/gradual) system: it can be| sorbet.org
Sorbet can track when a value is allowed to be `nil`, or when a value of a| sorbet.org