diff --git a/src/harness/fourslash.ts b/src/harness/fourslash.ts
index 6a4e13b22e3..9dad3dddf60 100644
--- a/src/harness/fourslash.ts
+++ b/src/harness/fourslash.ts
@@ -146,7 +146,7 @@ module FourSlash {
 
     function convertGlobalOptionsToCompilationSettings(globalOptions: { [idx: string]: string }): ts.CompilationSettings {
         var settings: ts.CompilationSettings = {};
-    // Convert all property in globalOptions into ts.CompilationSettings
+        // Convert all property in globalOptions into ts.CompilationSettings
         for (var prop in globalOptions) {
             if (globalOptions.hasOwnProperty(prop)) {
                 switch (prop) {
@@ -1610,7 +1610,7 @@ module FourSlash {
             Harness.IO.log(this.getNameOrDottedNameSpan(pos));
         }
 
-        private verifyClassifications(expected: { classificationType: string; text: string }[], actual: ts.ClassifiedSpan[]) {
+        private verifyClassifications(expected: { classificationType: string; text: string; textSpan?: TextSpan }[], actual: ts.ClassifiedSpan[]) {
             if (actual.length !== expected.length) {
                 this.raiseError('verifyClassifications failed - expected total classifications to be ' + expected.length + ', but was ' + actual.length);
             }
@@ -1626,7 +1626,19 @@ module FourSlash {
                         actualClassification.classificationType);
                 }
 
+                var expectedSpan = expectedClassification.textSpan;
                 var actualSpan = actualClassification.textSpan;
+
+                if (expectedSpan) {
+                    var expectedLength = expectedSpan.end - expectedSpan.start;
+
+                    if (expectedSpan.start !== actualSpan.start() || expectedLength !== actualSpan.length()) {
+                        this.raiseError("verifyClassifications failed - expected span of text to be " +
+                            "{start=" + expectedSpan.start + ", length=" + expectedLength + "}, but was " +
+                            "{start=" + actualSpan.start() + ", length=" + actualSpan.length() + "}");
+                    }
+                }
+
                 var actualText = this.activeFile.content.substr(actualSpan.start(), actualSpan.length());
                 if (expectedClassification.text !== actualText) {
                     this.raiseError('verifyClassifications failed - expected classificatied text to be ' +
diff --git a/tests/cases/fourslash/fourslash.ts b/tests/cases/fourslash/fourslash.ts
index 7be7dd63c92..d184be57712 100644
--- a/tests/cases/fourslash/fourslash.ts
+++ b/tests/cases/fourslash/fourslash.ts
@@ -80,6 +80,10 @@ module FourSlashInterface {
             return FourSlash.currentTestState.getMarkers();
         }
 
+        public marker(name?: string): Marker {
+            return FourSlash.currentTestState.getMarkerByName(name);
+        }
+
         public ranges(): Range[] {
             return FourSlash.currentTestState.getRanges();
         }
@@ -401,11 +405,17 @@ module FourSlashInterface {
             FourSlash.currentTestState.verifyCompletionEntryDetails(entryName, text, documentation, kind);
         }
 
+        /**
+         * This method *requires* a contiguous, complete, and ordered stream of classifications for a file.
+         */
         public syntacticClassificationsAre(...classifications: { classificationType: string; text: string }[]) {
             FourSlash.currentTestState.verifySyntacticClassifications(classifications);
         }
 
-        public semanticClassificationsAre(...classifications: { classificationType: string; text: string }[]) {
+        /**
+         * This method *requires* an ordered stream of classifications for a file, and spans are highly recommended.
+         */
+        public semanticClassificationsAre(...classifications: { classificationType: string; text: string; textSpan?: TextSpan }[]) {
             FourSlash.currentTestState.verifySemanticClassifications(classifications);
         }
 
@@ -563,61 +573,69 @@ module FourSlashInterface {
         }
     }
 
-    export class classification {
-        public static comment(text: string): { classificationType: string; text: string } {
-            return { classificationType: "comment", text: text };
+    export module classification {
+        export function comment(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("comment", text, position);
         }
 
-        public static identifier(text: string): { classificationType: string; text: string } {
-            return { classificationType: "identifier", text: text };
+        export function identifier(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("identifier", text, position);
         }
 
-        public static keyword(text: string): { classificationType: string; text: string } {
-            return { classificationType: "keyword", text: text };
+        export function keyword(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("keyword", text, position);
         }
 
-        public static numericLiteral(text: string): { classificationType: string; text: string } {
-            return { classificationType: "numericLiteral", text: text };
+        export function numericLiteral(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("numericLiteral", text, position);
         }
 
-        public static operator(text: string): { classificationType: string; text: string } {
-            return { classificationType: "operator", text: text };
+        export function operator(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("operator", text, position);
         }
 
-        public static stringLiteral(text: string): { classificationType: string; text: string } {
-            return { classificationType: "stringLiteral", text: text };
+        export function stringLiteral(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("stringLiteral", text, position);
         }
 
-        public static whiteSpace(text: string): { classificationType: string; text: string } {
-            return { classificationType: "whiteSpace", text: text };
+        export function whiteSpace(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("whiteSpace", text, position);
         }
 
-        public static text(text: string): { classificationType: string; text: string } {
-            return { classificationType: "text", text: text };
+        export function text(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("text", text, position);
         }
 
-        public static punctuation(text: string): { classificationType: string; text: string } {
-            return { classificationType: "punctuation", text: text };
+        export function punctuation(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("punctuation", text, position);
         }
 
-        public static className(text: string): { classificationType: string; text: string } {
-            return { classificationType: "className", text: text };
+        export function className(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("className", text, position);
         }
 
-        public static enumName(text: string): { classificationType: string; text: string } {
-            return { classificationType: "enumName", text: text };
+        export function enumName(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("enumName", text, position);
         }
 
-        public static interfaceName(text: string): { classificationType: string; text: string } {
-            return { classificationType: "interfaceName", text: text };
+        export function interfaceName(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("interfaceName", text, position);
         }
 
-        public static moduleName(text: string): { classificationType: string; text: string } {
-            return { classificationType: "moduleName", text: text };
+        export function moduleName(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("moduleName", text, position);
         }
 
-        public static typeParameterName(text: string): { classificationType: string; text: string } {
-            return { classificationType: "typeParameterName", text: text };
+        export function typeParameterName(text: string, position?: number): { classificationType: string; text: string; textSpan?: TextSpan } {
+            return getClassification("typeParameterName", text, position);
+        }
+
+        function getClassification(type: string, text: string, position?: number) {
+            return {
+                classificationType: type,
+                text: text,
+                textSpan: position === undefined ? undefined : { start: position, end: position + text.length }
+            };
         }
     }
 }
@@ -635,6 +653,7 @@ module fs {
 function verifyOperationIsCancelled(f) {
     FourSlash.verifyOperationIsCancelled(f);
 }
+
 var test = new FourSlashInterface.test_();
 var goTo = new FourSlashInterface.goTo();
 var verify = new FourSlashInterface.verify();
diff --git a/tests/cases/fourslash/semanticClassification1.ts b/tests/cases/fourslash/semanticClassification1.ts
index ad9e88ea842..4eb7f2a32ed 100644
--- a/tests/cases/fourslash/semanticClassification1.ts
+++ b/tests/cases/fourslash/semanticClassification1.ts
@@ -1,11 +1,15 @@
 /// <reference path="fourslash.ts"/>
 
-//// module M {
-////     export interface I {
+//// module /*0*/M {
+////     export interface /*1*/I {
 ////     }
 //// }
-//// interface X extends M.I { }
+//// interface /*2*/X extends /*3*/M./*4*/I { }
 
 var c = classification;
 verify.semanticClassificationsAre(
-    c.moduleName("M"), c.interfaceName("I"), c.interfaceName("X"), c.moduleName("M"), c.interfaceName("I"));
+    c.moduleName("M", test.marker("0").position),
+    c.interfaceName("I", test.marker("1").position),
+    c.interfaceName("X", test.marker("2").position),
+    c.moduleName("M", test.marker("3").position),
+    c.interfaceName("I", test.marker("4").position));
diff --git a/tests/cases/fourslash/semanticClassification2.ts b/tests/cases/fourslash/semanticClassification2.ts
index 810636dba3e..f7f6340e5bd 100644
--- a/tests/cases/fourslash/semanticClassification2.ts
+++ b/tests/cases/fourslash/semanticClassification2.ts
@@ -1,6 +1,6 @@
 /// <reference path="fourslash.ts"/>
 
-//// interface Thing {
+//// interface /*0*/Thing {
 ////     toExponential(): number;
 //// }
 //// 
@@ -8,4 +8,4 @@
 //// Thing.toExponential();
 
 var c = classification;
-verify.semanticClassificationsAre(c.interfaceName("Thing"));
\ No newline at end of file
+verify.semanticClassificationsAre(c.interfaceName("Thing", test.marker("0").position));
\ No newline at end of file
diff --git a/tests/cases/fourslash/semanticClassificationInstantiatedModuleWithVariableOfSameName1.ts b/tests/cases/fourslash/semanticClassificationInstantiatedModuleWithVariableOfSameName1.ts
index 96cce6f4255..2b8b6824558 100644
--- a/tests/cases/fourslash/semanticClassificationInstantiatedModuleWithVariableOfSameName1.ts
+++ b/tests/cases/fourslash/semanticClassificationInstantiatedModuleWithVariableOfSameName1.ts
@@ -1,20 +1,24 @@
 /// <reference path="fourslash.ts"/>
 
-////module M {
-////    export interface I {
+////module /*0*/M {
+////    export interface /*1*/I {
 ////    }
 ////    var x = 10;
 ////}
 ////
-////var M = {
+////var /*2*/M = {
 ////    foo: 10,
 ////    bar: 20
 ////}
 ////
-////var v: M.I;
+////var v: /*3*/M./*4*/I;
 ////
-////var x = M;
+////var x = /*5*/M;
 
 var c = classification;
 verify.semanticClassificationsAre(
-    c.moduleName("M"), c.interfaceName("I"), c.moduleName("M"), c.interfaceName("I"), c.moduleName("M"));
+    c.moduleName("M", test.marker("0").position),
+    c.interfaceName("I", test.marker("1").position),
+    c.moduleName("M", test.marker("3").position),
+    c.interfaceName("I", test.marker("4").position),
+    c.moduleName("M", test.marker("5").position));
diff --git a/tests/cases/fourslash/semanticClassificationInstantiatedModuleWithVariableOfSameName2.ts b/tests/cases/fourslash/semanticClassificationInstantiatedModuleWithVariableOfSameName2.ts
index bcbd5f514f4..5d2ed9844cc 100644
--- a/tests/cases/fourslash/semanticClassificationInstantiatedModuleWithVariableOfSameName2.ts
+++ b/tests/cases/fourslash/semanticClassificationInstantiatedModuleWithVariableOfSameName2.ts
@@ -1,23 +1,28 @@
 /// <reference path="fourslash.ts"/>
 
-////module M {
-////    export interface I {
+////module /*0*/M {
+////    export interface /*1*/I {
 ////    }
 ////}
 ////
-////module M {
+////module /*2*/M {
 ////    var x = 10;
 ////}
 ////
-////var M = {
+////var /*3*/M = {
 ////    foo: 10,
 ////    bar: 20
 ////}
 ////
-////var v: M.I;
+////var v: /*4*/M./*5*/I;
 ////
-////var x = M;
+////var x = /*6*/M;
 
 var c = classification;
 verify.semanticClassificationsAre(
-    c.moduleName("M"), c.interfaceName("I"), c.moduleName("M"), c.moduleName("M"), c.interfaceName("I"), c.moduleName("M"));
+    c.moduleName("M", test.marker("0").position),
+    c.interfaceName("I", test.marker("1").position),
+    c.moduleName("M", test.marker("2").position),
+    c.moduleName("M", test.marker("4").position),
+    c.interfaceName("I", test.marker("5").position),
+    c.moduleName("M", test.marker("6").position));
diff --git a/tests/cases/fourslash/semanticClassificationModules.ts b/tests/cases/fourslash/semanticClassificationModules.ts
index fc75b3bba98..86c2819983a 100644
--- a/tests/cases/fourslash/semanticClassificationModules.ts
+++ b/tests/cases/fourslash/semanticClassificationModules.ts
@@ -1,13 +1,19 @@
 /// <reference path="fourslash.ts"/>
 
-////module M {
+////module /*0*/M {
 ////    export var v;
-////    export interface I {
+////    export interface /*1*/I {
 ////    }
 ////}
 ////
-////var x: M.I = M.v;
-////var y = M;
+////var x: /*2*/M./*3*/I = /*4*/M.v;
+////var y = /*5*/M;
 
 var c = classification;
-verify.semanticClassificationsAre(c.moduleName("M"), c.interfaceName("I"), c.moduleName("M"), c.interfaceName("I"), c.moduleName("M"), c.moduleName("M"));
\ No newline at end of file
+verify.semanticClassificationsAre(
+    c.moduleName("M", test.marker("0").position),
+    c.interfaceName("I", test.marker("1").position),
+    c.moduleName("M", test.marker("2").position),
+    c.interfaceName("I", test.marker("3").position),
+    c.moduleName("M", test.marker("4").position),
+    c.moduleName("M", test.marker("5").position));
\ No newline at end of file
diff --git a/tests/cases/fourslash/semanticClassificationUninstantiatedModuleWithVariableOfSameName1.ts b/tests/cases/fourslash/semanticClassificationUninstantiatedModuleWithVariableOfSameName1.ts
index fb3717006fe..e7486c2c0cb 100644
--- a/tests/cases/fourslash/semanticClassificationUninstantiatedModuleWithVariableOfSameName1.ts
+++ b/tests/cases/fourslash/semanticClassificationUninstantiatedModuleWithVariableOfSameName1.ts
@@ -1,7 +1,7 @@
 /// <reference path="fourslash.ts"/>
 
-////declare module M {
-////    interface I {
+////declare module /*0*/M {
+////    interface /*1*/I {
 ////
 ////    }
 ////}
@@ -9,4 +9,6 @@
 ////var M = { I: 10 };
 
 var c = classification;
-verify.semanticClassificationsAre(c.moduleName("M"), c.interfaceName("I"));
\ No newline at end of file
+verify.semanticClassificationsAre(
+    c.moduleName("M", test.marker("0").position),
+    c.interfaceName("I", test.marker("1").position));
\ No newline at end of file
diff --git a/tests/cases/fourslash/semanticClassificationUninstantiatedModuleWithVariableOfSameName2.ts b/tests/cases/fourslash/semanticClassificationUninstantiatedModuleWithVariableOfSameName2.ts
index 295af091e75..f90efd7518d 100644
--- a/tests/cases/fourslash/semanticClassificationUninstantiatedModuleWithVariableOfSameName2.ts
+++ b/tests/cases/fourslash/semanticClassificationUninstantiatedModuleWithVariableOfSameName2.ts
@@ -1,19 +1,22 @@
 /// <reference path="fourslash.ts"/>
 
-////module M {
-////    export interface I {
+////module /*0*/M {
+////    export interface /*1*/I {
 ////    }
 ////}
 ////
-////var M = {
+////var /*2*/M = {
 ////    foo: 10,
 ////    bar: 20
 ////}
 ////
-////var v: M.I;
+////var v: /*3*/M./*4*/I;
 ////
-////var x = M;
+////var x = /*5*/M;
 
 var c = classification;
 verify.semanticClassificationsAre(
-    c.moduleName("M"), c.interfaceName("I"), c.moduleName("M"), c.interfaceName("I"));
+    c.moduleName("M", test.marker("0").position),
+    c.interfaceName("I", test.marker("1").position),
+    c.moduleName("M", test.marker("3").position),
+    c.interfaceName("I", test.marker("4").position));
diff --git a/tests/cases/fourslash/syntacticClassifications1.ts b/tests/cases/fourslash/syntacticClassifications1.ts
index e70a4b672ff..88f655683a3 100644
--- a/tests/cases/fourslash/syntacticClassifications1.ts
+++ b/tests/cases/fourslash/syntacticClassifications1.ts
@@ -18,7 +18,6 @@
 ////     }
 //// }
 
-debugger;
 var c = classification;
 verify.syntacticClassificationsAre(
     c.comment("// comment"),