diff --git a/packages/language-service/src/expression_diagnostics.ts b/packages/language-service/src/expression_diagnostics.ts
index 124f63e77a..84a6ff480f 100644
--- a/packages/language-service/src/expression_diagnostics.ts
+++ b/packages/language-service/src/expression_diagnostics.ts
@@ -269,10 +269,12 @@ class ExpressionDiagnosticsVisitor extends RecursiveTemplateAstVisitor {
       if (context && !context.has(ast.value)) {
         if (ast.value === '$implicit') {
           this.reportError(
-              'The template context does not have an implicit value', spanOf(ast.sourceSpan));
+              `The template context of '${directive.type.reference.name}' does not define an implicit value.\n` +
+                  `If the context type is a base type, consider refining it to a more specific type.`,
+              spanOf(ast.sourceSpan));
         } else {
           this.reportError(
-              `The template context does not define a member called '${ast.value}'`,
+              `The template context of '${directive.type.reference.name}' does not define a member called '${ast.value}'`,
               spanOf(ast.sourceSpan));
         }
       }
diff --git a/packages/language-service/test/diagnostics_spec.ts b/packages/language-service/test/diagnostics_spec.ts
index 4acdd08551..7ae5bf4e5e 100644
--- a/packages/language-service/test/diagnostics_spec.ts
+++ b/packages/language-service/test/diagnostics_spec.ts
@@ -25,7 +25,6 @@ import {MockTypescriptHost} from './test_utils';
 
 const EXPRESSION_CASES = '/app/expression-cases.ts';
 const NG_FOR_CASES = '/app/ng-for-cases.ts';
-const NG_IF_CASES = '/app/ng-if-cases.ts';
 const TEST_TEMPLATE = '/app/test.ng';
 const APP_COMPONENT = '/app/app.component.ts';
 
@@ -242,11 +241,6 @@ describe('diagnostics', () => {
           `and element references do not contain such a member`);
     });
 
-    it('should report an unknown context reference', () => {
-      const diags = ngLS.getSemanticDiagnostics(NG_FOR_CASES).map(d => d.messageText);
-      expect(diags).toContain(`The template context does not define a member called 'even_1'`);
-    });
-
     it('should report an unknown value in a key expression', () => {
       const diags = ngLS.getSemanticDiagnostics(NG_FOR_CASES).map(d => d.messageText);
       expect(diags).toContain(
@@ -256,10 +250,37 @@ describe('diagnostics', () => {
     });
   });
 
-  describe('in ng-if-cases.ts', () => {
-    it('should report an implicit context reference', () => {
-      const diags = ngLS.getSemanticDiagnostics(NG_IF_CASES).map(d => d.messageText);
-      expect(diags).toContain(`The template context does not define a member called 'unknown'`);
+  describe('embedded templates', () => {
+    it('should suggest refining a template context missing a property', () => {
+      mockHost.override(
+          TEST_TEMPLATE,
+          `<button type="button" ~{start-emb}*counter="let hero of heroes"~{end-emb}></button>`);
+      const diags = ngLS.getSemanticDiagnostics(TEST_TEMPLATE);
+      expect(diags.length).toBe(1);
+      const {messageText, start, length} = diags[0];
+      expect(messageText)
+          .toBe(
+              `The template context of 'CounterDirective' does not define an implicit value.\n` +
+                  `If the context type is a base type, consider refining it to a more specific type.`, );
+
+      const span = mockHost.getLocationMarkerFor(TEST_TEMPLATE, 'emb');
+      expect(start).toBe(span.start);
+      expect(length).toBe(span.length);
+    });
+
+    it('should report an unknown context reference', () => {
+      mockHost.override(
+          TEST_TEMPLATE,
+          `<div ~{start-emb}*ngFor="let hero of heroes; let e = even_1"~{end-emb}></div>`);
+      const diags = ngLS.getSemanticDiagnostics(TEST_TEMPLATE);
+      expect(diags.length).toBe(1);
+      const {messageText, start, length} = diags[0];
+      expect(messageText)
+          .toBe(`The template context of 'NgForOf' does not define a member called 'even_1'`);
+
+      const span = mockHost.getLocationMarkerFor(TEST_TEMPLATE, 'emb');
+      expect(start).toBe(span.start);
+      expect(length).toBe(span.length);
     });
   });
 
diff --git a/packages/language-service/test/project/app/main.ts b/packages/language-service/test/project/app/main.ts
index 31dab5c379..6de049e260 100644
--- a/packages/language-service/test/project/app/main.ts
+++ b/packages/language-service/test/project/app/main.ts
@@ -33,6 +33,7 @@ import * as ParsingCases from './parsing-cases';
     ParsingCases.CaseIncompleteOpen,
     ParsingCases.CaseMissingClosing,
     ParsingCases.CaseUnknown,
+    ParsingCases.CounterDirective,
     ParsingCases.EmptyInterpolation,
     ParsingCases.HintModel,
     ParsingCases.NoValueAttribute,
diff --git a/packages/language-service/test/project/app/parsing-cases.ts b/packages/language-service/test/project/app/parsing-cases.ts
index 77e6753add..90c90a9eaf 100644
--- a/packages/language-service/test/project/app/parsing-cases.ts
+++ b/packages/language-service/test/project/app/parsing-cases.ts
@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {Component, Directive, EventEmitter, Input, Output} from '@angular/core';
+import {Component, Directive, EventEmitter, Input, OnChanges, Output, SimpleChanges, TemplateRef, ViewContainerRef} from '@angular/core';
 
 import {Hero} from './app.component';
 
@@ -109,6 +109,24 @@ export class AsyncForUsingComponent {
 export class References {
 }
 
+class CounterDirectiveContext<T> {
+  constructor(public $implicit: T) {}
+}
+
+@Directive({selector: '[counterOf]'})
+export class CounterDirective implements OnChanges {
+  // Object does not have an "$implicit" property.
+  constructor(private container: ViewContainerRef, private template: TemplateRef<Object>) {}
+
+  @Input('counterOf') counter: number = 0;
+  ngOnChanges(_changes: SimpleChanges) {
+    this.container.clear();
+    for (let i = 0; i < this.counter; ++i) {
+      this.container.createEmbeddedView(this.template, new CounterDirectiveContext<number>(i + 1));
+    }
+  }
+}
+
 /**
  * This Component provides the `test-comp` selector.
  */