diff --git a/crates/lang/src/lst_parser.rs b/crates/lang/src/lst_parser.rs
index a6ec4d7..5c90bb0 100644
--- a/crates/lang/src/lst_parser.rs
+++ b/crates/lang/src/lst_parser.rs
@@ -111,7 +111,7 @@ impl Marker {
         }
     }
 
-    fn complete_node(mut self, p: &mut Parser, kind: NodeKind) -> CompletedMarker {
+    fn close_node(mut self, p: &mut Parser, kind: NodeKind) -> CompletedMarker {
         self.bomb.defuse();
         match &mut p.events[self.pos] {
             Event::Start { kind: slot, .. } => *slot = kind.clone(),
@@ -127,11 +127,11 @@ impl Marker {
     }
 
     pub(crate) fn complete(self, p: &mut Parser<'_, '_>, kind: SyntaxKind) -> CompletedMarker {
-        self.complete_node(p, NodeKind::Syntax(kind))
+        self.close_node(p, NodeKind::Syntax(kind))
     }
 
     pub(crate) fn error(self, p: &mut Parser, kind: SyntaxError) -> CompletedMarker {
-        self.complete_node(p, NodeKind::Error(kind))
+        self.close_node(p, NodeKind::Error(kind))
     }
 
     pub(crate) fn abandon(mut self, p: &mut Parser<'_, '_>) {
diff --git a/crates/lang/src/lst_parser/error.rs b/crates/lang/src/lst_parser/error.rs
index 7fa4431..04f5e7b 100644
--- a/crates/lang/src/lst_parser/error.rs
+++ b/crates/lang/src/lst_parser/error.rs
@@ -7,4 +7,7 @@ pub enum SyntaxError {
     // if there was two space seperated items in a list
     SpaceSepInList,
     SemicolonInList,
+    CommaInMatOrVec,
+    UnterminatedTopLevelItem,
+    UnclosedModuleBody,
 }
diff --git a/crates/lang/src/lst_parser/grammar.rs b/crates/lang/src/lst_parser/grammar.rs
index 9d081bb..2db0824 100644
--- a/crates/lang/src/lst_parser/grammar.rs
+++ b/crates/lang/src/lst_parser/grammar.rs
@@ -2,6 +2,8 @@ use std::fmt::Debug;
 
 use crate::lst_parser::syntax_kind::SyntaxKind::*;
 
+use self::module::{mod_body, top_level_item};
+
 use super::{
     input::Input,
     output::Output,
@@ -10,11 +12,13 @@ use super::{
 };
 
 mod expression;
+mod module;
 
 pub fn source_file(p: &mut Parser) {
     let root = p.start("root");
 
-    expression::expression(p, false);
+    mod_body(p);
+    // expression::expression(p, false);
     p.eat_succeeding_ws();
 
     root.complete(p, ROOT);
diff --git a/crates/lang/src/lst_parser/grammar/expression/collection/vec.rs b/crates/lang/src/lst_parser/grammar/expression/collection/vec.rs
index 385723b..4dfd299 100644
--- a/crates/lang/src/lst_parser/grammar/expression/collection/vec.rs
+++ b/crates/lang/src/lst_parser/grammar/expression/collection/vec.rs
@@ -25,7 +25,6 @@ pub fn vec_matrix_list(p: &mut Parser) -> CompletedMarker {
     }
 }
 
-// TODO: handle semicolons, other wrong toks
 fn finish_list(p: &mut Parser, list_start: Marker) -> CompletedMarker {
     loop {
         if p.eat(COMMA) {
@@ -41,11 +40,11 @@ fn finish_list(p: &mut Parser, list_start: Marker) -> CompletedMarker {
             item.precede(p, "next_item")
                 .complete(p, COLLECTION_ITEM)
                 .precede(p, "err_space_sep")
-                .complete_err(p, SyntaxError::SpaceSepInList);
+                .error(p, SyntaxError::SpaceSepInList);
         } else if p.at(SEMICOLON) {
             let semi_err = p.start("semicolon_err");
             p.eat(SEMICOLON);
-            semi_err.complete_err(p, SyntaxError::SemicolonInList);
+            semi_err.error(p, SyntaxError::SemicolonInList);
             if let Some(item) = atom(p) {
                 item.precede(p, "coll_item_start")
                     .complete(p, COLLECTION_ITEM);
@@ -85,6 +84,14 @@ fn finish_mat_or_vec(p: &mut Parser, coll_start: Marker, mut row_start: Marker)
                 p.eat(R_BRACK);
                 return coll_start.complete(p, VEC);
             }
+        } else if p.at(COMMA) {
+            let err_unexpected_comma = p.start("err_unexpected_comma");
+            p.do_bump();
+            err_unexpected_comma.error(p, SyntaxError::CommaInMatOrVec);
+        } else {
+            let err_unexpected = p.start("err_unexpected_tok");
+            p.do_bump();
+            err_unexpected.error(p, SyntaxError::Expected(vec![EXPR, SEMICOLON, R_BRACK]));
         }
     }
 }
diff --git a/crates/lang/src/lst_parser/grammar/module.rs b/crates/lang/src/lst_parser/grammar/module.rs
new file mode 100644
index 0000000..fe51d2c
--- /dev/null
+++ b/crates/lang/src/lst_parser/grammar/module.rs
@@ -0,0 +1,106 @@
+use enumset::enum_set;
+
+use crate::lst_parser::{
+    error::SyntaxError,
+    grammar::expression::expression,
+    syntax_kind::{SyntaxKind::*, TokenSet},
+    CompletedMarker, Parser,
+};
+
+const TOP_LEVEL_ITEM_START: TokenSet = enum_set!(DEF_KW | MOD_KW | USE_KW);
+
+pub fn mod_body(p: &mut Parser) {
+    loop {
+        if top_level_item(p).is_none() {
+            break;
+        }
+    }
+}
+
+fn mod_decl(p: &mut Parser) -> Option<CompletedMarker> {
+    let mod_start = p.start("module");
+    if !p.eat(MOD_KW) {
+        return None;
+    }
+
+    let mod_name = p.start("module_name");
+    if p.eat(IDENT) {
+        mod_name.complete(p, MODULE_NAME);
+    } else {
+        mod_name.error(p, SyntaxError::Expected(vec![IDENT]));
+    }
+
+    let mod_body_marker = p.start("mod_body");
+    if p.eat(SEMICOLON) {
+        mod_body_marker.abandon(p);
+        Some(mod_start.complete(p, MODULE))
+    } else if p.eat(L_BRACE) {
+        mod_body(p);
+        if !p.eat(R_BRACE) {
+            mod_body_marker
+                .complete(p, MODULE_BODY)
+                .precede(p, "unclosed_mod_body_err")
+                .error(p, SyntaxError::UnclosedModuleBody);
+        } else {
+            mod_body_marker.complete(p, MODULE_BODY);
+        }
+        Some(mod_start.complete(p, MODULE))
+    } else {
+        Some(mod_start.error(p, SyntaxError::Expected(vec![MODULE_BODY])))
+    }
+}
+
+pub fn top_level_item(p: &mut Parser) -> Option<CompletedMarker> {
+    if !TOP_LEVEL_ITEM_START.contains(p.current()) {
+        return None;
+    }
+    def(p).or_else(|| mod_decl(p))
+}
+
+fn def(p: &mut Parser) -> Option<CompletedMarker> {
+    let def_start = p.start("top_level_def");
+    if !p.eat(DEF_KW) {
+        def_start.abandon(p);
+        return None;
+    }
+
+    let def_name = p.start("def_name");
+    if p.eat(IDENT) {
+        def_name.complete(p, DEF_NAME);
+    } else {
+        def_name.error(p, SyntaxError::Expected(vec![IDENT]));
+    }
+
+    let maybe_expected_eq = p.start("maybe_expect_eq");
+    if !p.eat(EQ) {
+        maybe_expected_eq.error(p, SyntaxError::Expected(vec![EQ]));
+    } else {
+        maybe_expected_eq.abandon(p);
+    }
+
+    let body = p.start("def_body");
+    if expression(p, false).is_some() {
+        body.complete(p, DEF_BODY);
+    } else {
+        body.error(p, SyntaxError::Expected(vec![DEF_BODY]));
+    }
+
+    let def = def_start.complete(p, DEF);
+    Some(if p.eat(SEMICOLON) {
+        def
+    } else if TOP_LEVEL_ITEM_START.contains(p.current()) || p.at(EOF) {
+        def.precede(p, "unterminated_tl_item")
+            .error(p, SyntaxError::UnterminatedTopLevelItem)
+    } else {
+        def.precede(p, "err_unexpected")
+            .error(p, SyntaxError::Expected(vec![SEMICOLON]))
+    })
+}
+
+fn r#use(p: &mut Parser) -> Option<CompletedMarker> {
+    if !p.eat(USE_KW) {
+        return None;
+    }
+
+    todo!()
+}
diff --git a/crates/lang/src/lst_parser/syntax_kind.rs b/crates/lang/src/lst_parser/syntax_kind.rs
index 4914aeb..7b0fe41 100644
--- a/crates/lang/src/lst_parser/syntax_kind.rs
+++ b/crates/lang/src/lst_parser/syntax_kind.rs
@@ -30,6 +30,7 @@ pub enum SyntaxKind {
     #[token("mod")]
     MOD_KW,
     MODULE,
+    MODULE_NAME,
     MODULE_BODY,
     #[token("use")]
     USE_KW,
diff --git a/testfiles/test.owo b/testfiles/test.owo
index ac1af18..b50e5c6 100644
--- a/testfiles/test.owo
+++ b/testfiles/test.owo
@@ -1 +1,8 @@
-meow | gay |
+def hello_world = meow [ 1 2 ]
+
+def test
+
+mod hello {
+	def meow = uwu;
+}
+