diff --git a/trixy/trixy-lang_parser/docs/grammar.ebnf b/trixy/trixy-lang_parser/docs/grammar.ebnf
index 749149c..05ffca8 100644
--- a/trixy/trixy-lang_parser/docs/grammar.ebnf
+++ b/trixy/trixy-lang_parser/docs/grammar.ebnf
@@ -6,11 +6,13 @@
 #  - Block comments (`/* */`).
 # *)
 
-CommandSpec = { Function | Namespace } ;
-Function = "fn" Identifier "(" {Identifier ":" Type} ")" [ "->" Type ] ";" ;
-Namespace = "nasp" Identifier "{" {Function | Namespace} "}" ;
-Type = "String" | "Integer" ; # (* This corresponds to the CommandTransferValue *)
+CommandSpec = { Function | Namespace | Enumeration | Structure } ;
+Function = "fn" Identifier "(" [NamedType {"," NamedType }] ")" [ "->" Type ] ";" ;
+Namespace = "nasp" Identifier "{" {Function | Namespace | Enumeration | Structure} "}" ;
+Structure = "struct" Identifier "{"  [NamedType {"," NamedType } [","]] "}" ";";
+Enumeration = "enum" Identifier "{"  [Identifier {"," Identifier} [","]] "}" ";";
 Identifier = CHARACTER { NUMBER | CHARACTER } ;
+NamedType = Identifier ":" Type;
 
 # (*
 #  vim: ft=ebnf
diff --git a/trixy/trixy-lang_parser/docs/grammar.pdf b/trixy/trixy-lang_parser/docs/grammar.pdf
index 54cad09..bf84bb0 100644
Binary files a/trixy/trixy-lang_parser/docs/grammar.pdf and b/trixy/trixy-lang_parser/docs/grammar.pdf differ
diff --git a/trixy/trixy-lang_parser/example/multiple.tri b/trixy/trixy-lang_parser/example/multiple.tri
index a0d01ad..0fca007 100644
--- a/trixy/trixy-lang_parser/example/multiple.tri
+++ b/trixy/trixy-lang_parser/example/multiple.tri
@@ -5,7 +5,7 @@ nasp trinitrix {
 }
 
 nasp trinitrix {
-    fn ho(name: String) -> String;
+    fn ho(name: String, name2: String) -> String;
 }
 
 
diff --git a/trixy/trixy-lang_parser/example/types.tri b/trixy/trixy-lang_parser/example/types.tri
new file mode 100644
index 0000000..b599445
--- /dev/null
+++ b/trixy/trixy-lang_parser/example/types.tri
@@ -0,0 +1,18 @@
+nasp trinitrix {
+    struct Callback {
+        func: Function,
+        timeout: Integer,
+    };
+
+    enum CallbackPriority {
+        High,
+        Medium,
+        Low,
+    };
+
+    fn execute_callback(callback: Callback, priority: CallbackPriority);
+}
+
+
+// That's a flat out lie, but it results in a rather nice syntax highlight compared to nothing:
+// vim: syntax=rust
diff --git a/trixy/trixy-lang_parser/src/command_spec/unchecked.rs b/trixy/trixy-lang_parser/src/command_spec/unchecked.rs
index ec2fa66..c7d2dc5 100644
--- a/trixy/trixy-lang_parser/src/command_spec/unchecked.rs
+++ b/trixy/trixy-lang_parser/src/command_spec/unchecked.rs
@@ -17,7 +17,22 @@ pub struct Declaration {
 
 impl Declaration {
     pub fn new_function(function: Function, namespace: Vec<Token>) -> Self {
-        Declaration { namespace, genus: Genus::Function(function) }
+        Declaration {
+            namespace,
+            genus: Genus::Function(function),
+        }
+    }
+    pub fn new_structure(structure: Structure, namespace: Vec<Token>) -> Self {
+        Declaration {
+            namespace,
+            genus: Genus::Structure(structure),
+        }
+    }
+    pub fn new_enumeration(r#enum: Enumeration, namespace: Vec<Token>) -> Self {
+        Declaration {
+            namespace,
+            genus: Genus::Enumeration(r#enum),
+        }
     }
 }
 
@@ -32,17 +47,31 @@ pub enum Genus {
     Dummy,
     /// A function
     Function(Function),
+    Structure(Structure),
+    Enumeration(Enumeration),
 }
 
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct Function {
     pub identifier: Token, // Will later become an Identifier
-    pub inputs: Vec<FunctionInput>,
+    pub inputs: Vec<NamedType>,
     pub output: Option<Token>, // Will later become an Type
 }
 
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
-pub struct FunctionInput {
-    pub name: Token, // Will later become an Identifier
+pub struct Structure {
+    pub identifier: Token, // Will later become an Identifier
+    pub contents: Vec<NamedType>,
+}
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Enumeration {
+    pub identifier: Token, // Will later become an Identifier
+    pub states: Vec<Token>, // Will later become an Identifier
+}
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub struct NamedType {
+    pub name: Token,   // Will later become an Identifier
     pub r#type: Token, // Will later become an Type
 }
diff --git a/trixy/trixy-lang_parser/src/lexing/mod.rs b/trixy/trixy-lang_parser/src/lexing/mod.rs
index 989ec8b..a8ecd6c 100644
--- a/trixy/trixy-lang_parser/src/lexing/mod.rs
+++ b/trixy/trixy-lang_parser/src/lexing/mod.rs
@@ -169,6 +169,12 @@ pub enum Keyword {
     /// Start a function declaration
     #[allow(non_camel_case_types)]
     r#fn,
+    /// Start a structure declaration
+    #[allow(non_camel_case_types)]
+    r#struct,
+    /// Start a enum declaration
+    #[allow(non_camel_case_types)]
+    r#enum,
 }
 
 impl Display for Keyword {
@@ -176,6 +182,8 @@ impl Display for Keyword {
         match self {
             Keyword::nasp => f.write_str("nasp"),
             Keyword::r#fn => f.write_str("fn"),
+            Keyword::r#struct => f.write_str("struct"),
+            Keyword::r#enum => f.write_str("enum"),
         }
     }
 }
@@ -214,6 +222,8 @@ macro_rules! token {
 
     [nasp] => { $crate::lexing::TokenKind::Keyword($crate::lexing::Keyword::nasp) };
     [fn] => { $crate::lexing::TokenKind::Keyword($crate::lexing::Keyword::r#fn) };
+    [struct] => { $crate::lexing::TokenKind::Keyword($crate::lexing::Keyword::r#struct) };
+    [enum] => { $crate::lexing::TokenKind::Keyword($crate::lexing::Keyword::r#enum) };
 
     // This is only works for checking for a identifier
     // see the `same_kind` method on TokenKind
diff --git a/trixy/trixy-lang_parser/src/lexing/tokenizer.rs b/trixy/trixy-lang_parser/src/lexing/tokenizer.rs
index af46d43..3e78ed7 100644
--- a/trixy/trixy-lang_parser/src/lexing/tokenizer.rs
+++ b/trixy/trixy-lang_parser/src/lexing/tokenizer.rs
@@ -91,8 +91,6 @@ impl<'a> Tokenizer<'a> {
             remaining = &remaining[ws..];
             ws
         };
-        // let comments = skip_comments(remaining);
-        // remaining = &remaining[comments..];
 
         let skip = self.remaining_text.len() - remaining.len();
         self.chomp(skip);
@@ -128,6 +126,8 @@ fn tokenize_ident(text: &str) -> Result<(TokenKind, usize), LexingError> {
     let tokenkind = match got {
         "nasp" => TokenKind::Keyword(Keyword::nasp),
         "fn" => TokenKind::Keyword(Keyword::r#fn),
+        "struct" => TokenKind::Keyword(Keyword::r#struct),
+        "enum" => TokenKind::Keyword(Keyword::r#enum),
         other => TokenKind::Identifier(other.to_string()),
     };
 
diff --git a/trixy/trixy-lang_parser/src/parsing/unchecked.rs b/trixy/trixy-lang_parser/src/parsing/unchecked.rs
index 9d12a9e..07f9423 100644
--- a/trixy/trixy-lang_parser/src/parsing/unchecked.rs
+++ b/trixy/trixy-lang_parser/src/parsing/unchecked.rs
@@ -1,5 +1,7 @@
 use crate::{
-    command_spec::unchecked::{CommandSpec, Declaration, Function, FunctionInput},
+    command_spec::unchecked::{
+        CommandSpec, Declaration, Enumeration, Function, NamedType, Structure,
+    },
     error::ErrorContext,
     lexing::{Token, TokenKind, TokenStream},
     token,
@@ -52,6 +54,14 @@ impl Parser {
                 self.parse_function()?,
                 self.current_namespaces.clone(),
             )]),
+            token![struct] => Ok(vec![Declaration::new_structure(
+                self.parse_structure()?,
+                self.current_namespaces.clone(),
+            )]),
+            token![enum] => Ok(vec![Declaration::new_enumeration(
+                self.parse_enumeration()?,
+                self.current_namespaces.clone(),
+            )]),
             _ => {
                 let err = ParsingError::ExpectedKeyword {
                     span: *self.peek().span(),
@@ -79,20 +89,73 @@ impl Parser {
         Ok(declarations)
     }
 
+    fn parse_enumeration(&mut self) -> Result<Enumeration, ParsingError> {
+        self.expect(token![enum])?;
+        let identifier = self.expect(token![Ident])?;
+        self.expect(token![BraceOpen])?;
+
+        let mut states = vec![];
+        if self.expect_peek(token![Ident]) {
+            states.push(self.expect(token![Ident])?);
+        }
+        while self.expect_peek(token![Comma]) {
+            self.expect(token![Comma])?;
+            if self.expect_peek(token![Ident]) {
+                states.push(self.expect(token![Ident])?);
+            } else {
+                break;
+            }
+        }
+        self.expect(token![BraceClose])?;
+        self.expect(token![;])?;
+        Ok(Enumeration { identifier, states })
+    }
+
+    fn parse_structure(&mut self) -> Result<Structure, ParsingError> {
+        self.expect(token![struct])?;
+        let name = self.expect(token![Ident])?;
+        self.expect(token![BraceOpen])?;
+
+        let mut contents = vec![];
+        if self.expect_peek(token![Ident]) {
+            contents.push(self.parse_named_type()?);
+        }
+        while self.expect_peek(token![Comma]) {
+            self.expect(token![Comma])?;
+            if self.expect_peek(token![Ident]) {
+                contents.push(self.parse_named_type()?);
+            } else {
+                break;
+            }
+        }
+        self.expect(token![BraceClose])?;
+        self.expect(token![;])?;
+
+        Ok(Structure {
+            identifier: name,
+            contents,
+        })
+    }
+
+    fn parse_named_type(&mut self) -> Result<NamedType, ParsingError> {
+        let name = self.expect(token![Ident])?;
+        self.expect(token![Colon])?;
+        let r#type = self.expect(token![Ident])?;
+        Ok(NamedType { name, r#type })
+    }
+
     fn parse_function(&mut self) -> Result<Function, ParsingError> {
         self.expect(token![fn])?;
         let name = self.expect(token![Ident])?;
         self.expect(token![ParenOpen])?;
         let mut inputs = vec![];
 
-        while self.expect_peek(token![Ident]) {
-            let input_name = self.expect(token![Ident])?;
-            self.expect(token![Colon])?;
-            let input_type = self.expect(token![Ident])?;
-            inputs.push(FunctionInput {
-                name: input_name,
-                r#type: input_type,
-            })
+        if self.expect_peek(token![Ident]) {
+            inputs.push(self.parse_named_type()?);
+        }
+        while self.expect_peek(token![Comma]) {
+            self.expect(token![Comma])?;
+            inputs.push(self.parse_named_type()?);
         }
 
         self.expect(token![ParenClose])?;