diff --git a/firestore.rules b/firestore.rules
index e73e464..4a6986b 100644
--- a/firestore.rules
+++ b/firestore.rules
@@ -226,5 +226,9 @@ service cloud.firestore {
 		match /completed_progress/{setIds} {
 			allow get: if isSignedIn();
 		}
+
+		match /incorrect_answers/{incorrectAnswerId} {
+			allow read: if isSignedIn();
+		}
   	}
 }
diff --git a/functions/index.js b/functions/index.js
index 3e7183d..9dd960a 100644
--- a/functions/index.js
+++ b/functions/index.js
@@ -434,17 +434,12 @@ exports.processAnswer = functions.https.onCall((data, context) => {
 				const currentIndex = progressDoc.data().progress;
 				const currentVocab = progressDoc.data().questions[currentIndex];
 
-				let answerDocId;
-
-				if (progressDoc.data().switch_language) {
-					answerDocId = progressDocId
+				termDocId = progressDocId
 						.collection("terms").doc(currentVocab);
-				} else {
-					answerDocId = progressDocId
+				definitionDocId = progressDocId
 						.collection("definitions").doc(currentVocab);
-				}
 
-				return transaction.get(answerDocId).then((answerDoc) => {
+				return transaction.get(progressDoc.data().switch_language ? termDocId : definitionDocId).then((answerDoc) => {
 					const docData = progressDoc.data();
 					const mode = docData.mode;
 					const correctAnswers = answerDoc.data().item;
@@ -507,6 +502,8 @@ exports.processAnswer = functions.https.onCall((data, context) => {
 
 					docData.typo = false;
 
+					var userGroups, incorrectAnswerDoc, prompt;
+
 					if (isCorrectAnswer) {
 						if (mode === "lives") {
 							returnData.lives = docData.lives;
@@ -542,8 +539,13 @@ exports.processAnswer = functions.https.onCall((data, context) => {
 						docData.questions = doneQuestions.concat(shuffleArray(notDoneQuestions));
 						returnData.totalQuestions = docData.questions.length;
 						returnData.totalIncorrect = docData.incorrect.length;
+
+						userGroups = transaction.get(db.collection("users").doc(uid).collection("groups")).then((querySnapshot) => querySnapshot.docs.map((doc) => doc.id));
+						incorrectAnswerDoc = db.collection("incorrect_answers").doc();
+						prompt = transaction.get(progressDoc.data().switch_language ? definitionDocId : termDocId).then((doc) => doc.data().item);
 					}
 
+
 					if (!returnData.moreAnswers) {
 						if (docData.progress >= docData.questions.length || (mode === "lives" && docData.lives <= 0)) {
 							const duration = Date.now() - docData.start_time;
@@ -554,7 +556,16 @@ exports.processAnswer = functions.https.onCall((data, context) => {
 							if (mode === "lives" && docData.lives <= 0) docData.questions.length = returnData.totalQuestions = docData.progress;
 							
 							const completedProgressDocId = db.collection("completed_progress").doc(progressDoc.data().setIds.sort().join("__"));
-							return transaction.get(completedProgressDocId).then((completedProgressDoc) => {
+							return transaction.get(completedProgressDocId).then(async (completedProgressDoc) => {
+								if (!isCorrectAnswer) transaction.set(incorrectAnswerDoc, {
+									uid: uid,
+									groups: await userGroups,
+									term: progressDoc.data().switch_language ? correctAnswers : await prompt,
+									definition: progressDoc.data().switch_language ? await prompt : correctAnswers,
+									answer: inputAnswer.trim(),
+									switch_language: progressDoc.data().switch_language,
+								});
+
 								const totalPercentage = completedProgressDoc.data().total_percentage + (docData.correct.length / docData.questions.length * 100);
 								const attempts = completedProgressDoc.data().attempts + 1;
 								transaction.set(completedProgressDocId, {
@@ -564,7 +575,16 @@ exports.processAnswer = functions.https.onCall((data, context) => {
 								returnData.averagePercentage = (totalPercentage / attempts).toFixed(2);
 								transaction.set(progressDocId, docData);
 								return returnData;
-							}).catch((error) => {
+							}).catch(async (error) => {
+								if (!isCorrectAnswer) transaction.set(incorrectAnswerDoc, {
+									uid: uid,
+									groups: await userGroups,
+									term: progressDoc.data().switch_language ? correctAnswers : await prompt,
+									definition: progressDoc.data().switch_language ? await prompt : correctAnswers,
+									answer: inputAnswer.trim(),
+									switch_language: progressDoc.data().switch_language,
+								});
+
 								const totalPercentage = docData.correct.length / docData.questions.length * 100;
 								transaction.set(completedProgressDocId, {
 									attempts: 1,
@@ -583,7 +603,16 @@ exports.processAnswer = functions.https.onCall((data, context) => {
 									.collection("definitions").doc(nextVocabId);
 								const sound = null;
 	
-								return transaction.get(promptDocId).then((promptDoc) => {
+								return transaction.get(promptDocId).then(async (promptDoc) => {
+									if (!isCorrectAnswer) transaction.set(incorrectAnswerDoc, {
+										uid: uid,
+										groups: await userGroups,
+										term: progressDoc.data().switch_language ? correctAnswers : await prompt,
+										definition: progressDoc.data().switch_language ? await prompt : correctAnswers,
+										answer: inputAnswer.trim(),
+										switch_language: progressDoc.data().switch_language,
+									});
+
 									returnData.nextPrompt = {
 										item: promptDoc.data().item,
 										sound: sound,
@@ -596,7 +625,16 @@ exports.processAnswer = functions.https.onCall((data, context) => {
 								const promptDocId = progressDocId
 									.collection("terms").doc(nextVocabId);
 	
-								return transaction.get(promptDocId).then((promptDoc) => {
+								return transaction.get(promptDocId).then(async (promptDoc) => {
+									if (!isCorrectAnswer) transaction.set(incorrectAnswerDoc, {
+										uid: uid,
+										groups: await userGroups,
+										term: progressDoc.data().switch_language ? correctAnswers : await prompt,
+										definition: progressDoc.data().switch_language ? await prompt : correctAnswers,
+										answer: inputAnswer.trim(),
+										switch_language: progressDoc.data().switch_language,
+									});
+
 									const sound = promptDoc.data().sound;
 									returnData.nextPrompt = {
 										item: promptDoc.data().item,
diff --git a/src/App.js b/src/App.js
index 3a46891..bd66eae 100644
--- a/src/App.js
+++ b/src/App.js
@@ -14,6 +14,7 @@ import UserSets from "./UserSets";
 import EditSet from "./EditSet";
 import Error404 from "./Error404";
 import History from "./History";
+import MistakesHistory from "./MistakesHistory";
 import TermsOfService from "./TermsOfService";
 import PrivacyPolicy from "./PrivacyPolicy";
 import Button from "./Button";
@@ -320,6 +321,9 @@ class App extends React.Component {
                 <Route path="/history" exact>
                   <History db={db} user={this.state.user} logEvent={analytics.logEvent} page={this.page} />
                 </Route>
+                <Route path="/history/mistakes" exact>
+                  <MistakesHistory db={db} user={this.state.user} logEvent={analytics.logEvent} page={this.page} />
+                </Route>
                 <Route path="/tos" exact>
                   <TermsOfService logEvent={analytics.logEvent} page={this.page} />
                 </Route>
diff --git a/src/History.js b/src/History.js
index 62bcffd..1edcdb6 100644
--- a/src/History.js
+++ b/src/History.js
@@ -1,5 +1,5 @@
 import React, { Component } from 'react';
-import { HomeRounded as HomeRoundedIcon, QuestionAnswerRounded as QuestionAnswerRoundedIcon, PeopleRounded as PeopleRoundedIcon, SwapHorizRounded as SwapHorizRoundedIcon, DeleteRounded as DeleteRoundedIcon } from "@material-ui/icons";
+import { TimelineRounded as TimelineRoundedIcon, HomeRounded as HomeRoundedIcon, QuestionAnswerRounded as QuestionAnswerRoundedIcon, PeopleRounded as PeopleRoundedIcon, SwapHorizRounded as SwapHorizRoundedIcon, DeleteRounded as DeleteRoundedIcon } from "@material-ui/icons";
 import NavBar from "./NavBar";
 import Button from "./Button";
 import Footer from "./Footer";
@@ -15,6 +15,13 @@ export default class History extends Component {
 			user: props.user,
 			db: props.db,
 			navbarItems: [
+				{
+					type: "link",
+					name: "Mistakes",
+					link: "/history/mistakes",
+					icon: <TimelineRoundedIcon />,
+					hideTextMobile: true,
+				},
 				{
 					type: "link",
 					link: "/",
diff --git a/src/MistakesHistory.js b/src/MistakesHistory.js
new file mode 100644
index 0000000..cbb2bbb
--- /dev/null
+++ b/src/MistakesHistory.js
@@ -0,0 +1,209 @@
+import React, { Component } from 'react';
+import { HistoryRounded as HistoryRoundedIcon, HomeRounded as HomeRoundedIcon, QuestionAnswerRounded as QuestionAnswerRoundedIcon, PeopleRounded as PeopleRoundedIcon, SwapHorizRounded as SwapHorizRoundedIcon, DeleteRounded as DeleteRoundedIcon } from "@material-ui/icons";
+import NavBar from "./NavBar";
+import Footer from "./Footer";
+import "./css/History.css";
+import "./css/MistakesHistory.css";
+
+export default class IncorrectHistory extends Component {
+	constructor(props) {
+		super(props);
+		this.state = {
+			user: props.user,
+			db: props.db,
+			navbarItems: [
+				{
+					type: "link",
+					name: "History",
+					link: "/history",
+					icon: <HistoryRoundedIcon />,
+					hideTextMobile: true,
+				},
+				{
+					type: "link",
+					link: "/",
+					icon: <HomeRoundedIcon />,
+					hideTextMobile: true,
+				}
+			],
+			incorrectAnswers: [],
+			totalIncorrect: 0,
+			totalTests: 0,
+		};
+
+		let isMounted = true;
+		Object.defineProperty(this, "isMounted", {
+			get: () => isMounted,
+			set: (value) => isMounted = value,
+		});
+	}
+
+	setState = (state, callback = null) => {
+		if (this.isMounted) super.setState(state, callback);
+	}
+
+	async componentDidMount() {
+		document.title = "Incorrect | History | Parandum";
+
+		let promises = [];
+		let newState = {};
+
+		promises.push(
+			this.state.db.collection("incorrect_answers")
+				.where("uid", "==", this.state.user.uid)
+				.orderBy("term", "asc")
+				.get()
+				.then((querySnapshot) => {
+					let incorrectAnswers = [];
+					querySnapshot.docs.map((doc, index, array) => {
+						if (index === 0 || doc.data().term !== array[index - 1].data().term || doc.data().definition !== array[index - 1].data().definition) {
+							incorrectAnswers.push({
+								term: doc.data().term,
+								definition: doc.data().definition,
+								answers: [{
+									answer: doc.data().answer,
+									switchLanguage: doc.data().switch_language,
+								}],
+								count: doc.data().switch_language ? 0 : 1,
+								switchedCount: doc.data().switch_language ? 1 : 0,
+							});
+						} else {
+							incorrectAnswers[incorrectAnswers.length - 1].answers.push({
+								answer: doc.data().answer,
+								switchLanguage: doc.data().switch_language,
+							});
+							if (doc.data().switch_language) {
+								incorrectAnswers[incorrectAnswers.length - 1].switchedCount++;
+							} else {
+								incorrectAnswers[incorrectAnswers.length - 1].count++;
+							}
+						}
+						return true;
+					});
+					newState.incorrectAnswers = incorrectAnswers.sort((a,b) => b.count + b.switchedCount - a.count - a.switchedCount);
+					newState.totalIncorrect = querySnapshot.docs.length;
+			})
+		);
+
+		promises.push(
+			this.state.db.collection("progress")
+				.where("uid", "==", this.state.user.uid)
+				.get()
+				.then((querySnapshot) => newState.totalTests = querySnapshot.docs.length)
+		);
+
+		await Promise.all(promises);
+
+		this.setState(newState);
+
+		this.props.page.load();
+
+		this.props.logEvent("page_view");
+	}
+
+	componentWillUnmount() {
+		this.isMounted = false;
+		this.props.page.unload();
+	}
+
+	msToTime = (time) => {
+		const localeData = {
+			minimumIntegerDigits: 2,
+			useGrouping: false,
+		};
+		const seconds = Math.floor((time / 1000) % 60).toLocaleString("en-GB", localeData);
+		const minutes = Math.floor((time / 1000 / 60) % 60).toLocaleString("en-GB", localeData);
+		const hours = Math.floor(time / 1000 / 60 / 60).toLocaleString("en-GB", localeData);
+
+		return `${hours}:${minutes}:${seconds}`;
+	}
+
+	render() {
+		return (
+			<div>
+				<NavBar items={this.state.navbarItems} />
+				<main>
+					<h1>Mistakes</h1>
+
+					<div className="history-sections">
+						<div className="historical-user-stats-container">
+							<div className="stat-row stat-row--inline">
+								<h1>{this.state.totalIncorrect}</h1>
+								<p>mistakes</p>
+							</div>
+							{
+								this.state.incorrectAnswers.length > 0 &&
+								<div className="stat-row stat-row--inline">
+									<h1>{this.state.incorrectAnswers[0].definition}</h1>
+									<p>meaning</p>
+									<h1>{this.state.incorrectAnswers[0].term}</h1>
+									<p>is the most common</p>
+								</div>
+							}
+							{
+								this.state.totalTests > 0 &&
+								<div className="stat-row stat-row--inline">
+									<h1>{(this.state.totalIncorrect / this.state.totalTests).toFixed(2)}</h1>
+									<p>mistakes per test on average</p>
+								</div>
+							}
+						</div>
+						<div className="mistakes-history-container">
+							{
+								this.state.incorrectAnswers.map((vocabItem) => (
+									<>
+										<div>
+											<h2>{vocabItem.term}</h2>
+											<p><b>{vocabItem.switchedCount} mistake{vocabItem.switchedCount !== 1 && "s"}{vocabItem.switchedCount > 0 && ":"}</b></p>
+											{
+												vocabItem.switchedCount > 0 &&
+												<div>
+													{
+														vocabItem.answers.sort((a, b) => {
+															if (a.answer < b.answer) {
+																return -1;
+															}
+															if (a.answer > b.answer) {
+																return 1;
+															}
+															return 0;
+														}).map((answerItem) => answerItem.switchLanguage && (
+															<p>{answerItem.answer === "" ? <i>skipped</i> : answerItem.answer}</p>
+														))
+													}
+												</div>
+											}
+										</div>
+										<div>
+											<h2>{vocabItem.definition}</h2>
+											<p><b>{vocabItem.count} mistake{vocabItem.count !== 1 && "s"}{vocabItem.count > 0 && ":"}</b></p>
+											{
+												vocabItem.count > 0 &&
+												<div>
+													{
+														vocabItem.answers.sort((a,b) => {
+															if (a.answer < b.answer) {
+																return -1;
+															}
+															if (a.answer > b.answer) {
+																return 1;
+															}
+															return 0;
+														}).map((answerItem) => !answerItem.switchLanguage && (
+															<p>{answerItem.answer === "" ? <i>skipped</i> : answerItem.answer}</p>
+														))
+													}
+												</div>
+											}
+										</div>
+									</>
+								))
+							}
+						</div>
+					</div>
+				</main>
+				<Footer />
+			</div>
+		)
+	}
+}
diff --git a/src/css/MistakesHistory.css b/src/css/MistakesHistory.css
new file mode 100644
index 0000000..76353b9
--- /dev/null
+++ b/src/css/MistakesHistory.css
@@ -0,0 +1,17 @@
+.mistakes-history-container {
+	display: grid;
+	grid-column-gap: 12px;
+	grid-template-columns: repeat(2, minmax(110px,max-content));
+	width: min-content;
+	word-wrap: break-word;
+  	word-break: break-word;
+	width: 100%;
+}
+
+.mistakes-history-container > div {
+	margin-bottom: 4px;
+}
+
+.mistakes-history-container > div:last-child {
+	margin-bottom: 0;
+}
\ No newline at end of file