diff --git a/src/evaluate/evaluate.rs b/src/evaluate/evaluate.rs
index 6199654..df50812 100644
--- a/src/evaluate/evaluate.rs
+++ b/src/evaluate/evaluate.rs
@@ -43,7 +43,7 @@ pub fn evaluate(t: &Expression, context: &mut Context, allow_incomplete: bool) -
 
 			let new = match g {
 				Expression::Quantity(_, _) => None,
-
+				Expression::Tuple(_, _) => None,
 				Expression::Constant(_, c) => { Some(evaluate(&c.value(), context, false).unwrap()) },
 				Expression::Variable(l, s) => {
 					// Don't move up, re-evaluate
diff --git a/src/evaluate/function.rs b/src/evaluate/function.rs
index 8aacd9d..1255b4a 100644
--- a/src/evaluate/function.rs
+++ b/src/evaluate/function.rs
@@ -32,6 +32,15 @@ pub fn eval_function(g: &Expression) -> Result<Expression, (LineLocation, EvalEr
 
 	if args.len() != 1 {panic!()};
 	let a = &args[0];
+
+	// All the functions below take only one argument
+	if let Expression::Tuple(l, v) = a {
+		return Err((
+			*l + *loc,
+			EvalError::BadArguments(f.to_string(), 1, v.len())
+		))
+	};
+
 	let Expression::Quantity(l, q) = a else {panic!()};
 
 
diff --git a/src/evaluate/mod.rs b/src/evaluate/mod.rs
index 18f6831..aad128e 100644
--- a/src/evaluate/mod.rs
+++ b/src/evaluate/mod.rs
@@ -13,6 +13,7 @@ pub enum EvalError {
 	IncompatibleUnits(String, String),
 	Undefined(String),
 	EvaluationError,
+	BadArguments(String, usize, usize)
 }
 
 
@@ -39,6 +40,11 @@ impl ToString for EvalError {
 			},
 			EvalError::EvaluationError => {
 				String::from("Could not evaluate")
+			},
+			EvalError::BadArguments(s, want, got) => {
+				format!("{s} takes {want} argument{}, got {got}",
+					if *want == 1 {""} else {"s"},
+				)
 			}
 		}
 	}
diff --git a/src/evaluate/operator.rs b/src/evaluate/operator.rs
index 702df7d..d127a0a 100644
--- a/src/evaluate/operator.rs
+++ b/src/evaluate/operator.rs
@@ -1,3 +1,4 @@
+use std::collections::VecDeque;
 use crate::parser::LineLocation;
 use crate::quantity::Quantity;
 use crate::parser::Operator;
@@ -12,6 +13,31 @@ pub fn eval_operator(g: &Expression, _context: &mut Context) -> Result<Option<Ex
 
 	match op {
 		Operator::Function(_) => unreachable!("Functions are handled seperately."),
+		Operator::Tuple => {
+			if args.len() != 2 { panic!() };
+			let a = &args[0];
+			let b = &args[1];
+
+			let mut loc = *op_loc;
+			let mut vec: VecDeque<Expression> = VecDeque::new();
+			if let Expression::Tuple(l, v) = a {
+				loc += *l;
+				for i in v { vec.push_back(i.clone()) }
+			} else {
+				loc += a.get_linelocation();
+				vec.push_back(a.clone())
+			}
+
+			if let Expression::Tuple(l, v) = b {
+				loc += *l;
+				for i in v { vec.push_back(i.clone()) }
+			} else {
+				loc += b.get_linelocation();
+				vec.push_back(b.clone())
+			}
+
+			return Ok(Some(Expression::Tuple(loc, vec)))
+		}
 
 		Operator::Negative => {
 			if args.len() != 1 { panic!() };
diff --git a/src/parser/expression/expression.rs b/src/parser/expression/expression.rs
index fa1d5d6..74f9a61 100644
--- a/src/parser/expression/expression.rs
+++ b/src/parser/expression/expression.rs
@@ -14,6 +14,7 @@ pub enum Expression {
 	Quantity(LineLocation, Quantity),
 	Constant(LineLocation, Constant),
 	Operator(LineLocation, Operator, VecDeque<Expression>),
+	Tuple(LineLocation, VecDeque<Expression>),
 }
 
 impl ToString for Expression {
@@ -22,7 +23,15 @@ impl ToString for Expression {
 			Expression::Quantity(_, v) => v.to_string(),
 			Expression::Constant(_, c) => c.to_string(),
 			Expression::Variable(_, s) => s.clone(),
-			Expression::Operator(_, o,a) => o.print(a)
+			Expression::Operator(_, o,a) => o.print(a),
+			Expression::Tuple(_, v) => {
+				format!("({})",
+					v.iter()
+						.map(|x| x.to_string())
+						.collect::<Vec<String>>()
+						.join(", ")
+				)
+			}
 		}
 	}
 }
@@ -35,7 +44,15 @@ impl Expression {
 			Expression::Quantity(_, v) => v.to_string_outer(),
 			Expression::Constant(_, c) => c.to_string(),
 			Expression::Variable(_, s) => s.clone(),
-			Expression::Operator(_, o,a) => o.print(a)
+			Expression::Operator(_, o,a) => o.print(a),
+			Expression::Tuple(_, v) => {
+				format!("({})",
+					v.iter()
+						.map(|x| x.to_string())
+						.collect::<Vec<String>>()
+						.join(", ")
+				)
+			}
 		}
 	}
 
@@ -92,6 +109,7 @@ impl Expression {
 	pub fn get_args_mut(&mut self) -> Option<&mut VecDeque<Expression>> {
 		match self {
 			Expression::Operator(_, _, ref mut a) => Some(a),
+			Expression::Tuple(_, ref mut a) => Some(a),
 			_ => None
 		}
 	}
@@ -100,6 +118,7 @@ impl Expression {
 	pub fn get_args(&self) -> Option<&VecDeque<Expression>> {
 		match self {
 			Expression::Operator(_, _, ref a) => Some(a),
+			Expression::Tuple(_, ref a) => Some(a),
 			_ => None
 		}
 	}
@@ -134,6 +153,7 @@ impl Expression {
 			| Expression::Constant(l, _)
 			| Expression::Variable(l, _)
 			| Expression::Operator(l, _,_)
+			| Expression::Tuple(l, _)
 			=> { *l }
 		}
 	}
@@ -144,6 +164,7 @@ impl Expression {
 			Expression::Constant(l, _) => { *l = *loc },
 			Expression::Variable(l, _) => { *l = *loc },
 			Expression::Operator(l, _,_) => { *l = *loc },
+			Expression::Tuple(l, _) => { *l = *loc },
 		}
 	}
 }
\ No newline at end of file
diff --git a/src/parser/expression/operator.rs b/src/parser/expression/operator.rs
index a53d006..a6d16b6 100644
--- a/src/parser/expression/operator.rs
+++ b/src/parser/expression/operator.rs
@@ -13,7 +13,9 @@ use super::Function;
 pub enum Operator {
 	// When adding operators, don't forget to update help command text.
 	// It isn't automatically generated.
-	ModuloLong = 0, // Mod invoked with "mod"
+	Tuple = 0,
+
+	ModuloLong, // Mod invoked with "mod"
 	DivideLong, // Division invoked with "per"
 	UnitConvert,
 	Subtract,
@@ -67,6 +69,7 @@ impl Operator {
 		}
 
 		return match s {
+			","      => {Some( Operator::Tuple )},
 			"+"      => {Some( Operator::Add )},
 			"-"      => {Some( Operator::Subtract )},
 			"neg"    => {Some( Operator::Negative )},
@@ -143,6 +146,14 @@ impl Operator {
 
 	pub fn print(&self, args: &VecDeque<Expression>) -> String {
 		match self {
+			Operator::Tuple => {
+				return format!(
+					"{}, {}",
+					self.add_parens_to_arg(&args[0]),
+					self.add_parens_to_arg(&args[1])
+				);
+			},
+
 			Operator::Negative => {
 				return format!("-{}", self.add_parens_to_arg(&args[0]));
 			},
diff --git a/src/parser/stage/tokenize.rs b/src/parser/stage/tokenize.rs
index aeccfed..47b81b8 100644
--- a/src/parser/stage/tokenize.rs
+++ b/src/parser/stage/tokenize.rs
@@ -135,6 +135,14 @@ pub fn tokenize(input: &String) -> VecDeque<Token> {
 				};
 			},
 
+			',' => {
+				push_token(&mut g, t, i);
+				t = Some(Token::Operator(
+					LineLocation{pos: i, len: 1},
+					String::from(c)
+				));
+			},
+
 			// Operator
 			'^'|'!'|'%'|'\\'|
 			'*'|'×'|'/'|'÷'|