Recall from [Enabling runtime checks](/docs/runtime) that `sorbet-runtime` raises| sorbet.org
Sorbet is a gradual type checker, which is a blessing and a curse.| sorbet.org
This is one of three docs aimed at helping answer common questions about Sorbet:| sorbet.org
This doc will cover how to enable and disable the **static checks** that 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
| sorbet.org
## Step 1: Install dependencies| sorbet.org
Sorbet supports abstract classes, abstract methods, and interfaces. Abstract| sorbet.org
Sorbet has syntax for creating generic methods, classes, and interfaces.| sorbet.org
Sorbet can track when a value is allowed to be `nil`, or when a value of a| sorbet.org
RBI files are "Ruby Interface" files. Sorbet uses RBI files to learn about| sorbet.org