```html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">

<title>Minimal Pairs – "coal" and "goal" – Listening Discrimination</title>

<meta name="description" content="Listening discrimination practice contrasting /k/ and /g/ in British English.">
<meta name="keywords" content="British English,pronunciation,phonology,phonemes,minimal pairs,listening discrimination,language learning,teaching,efl,esl,elt">

<style>
@page {
    size: A4;
    margin: 20mm;
}

* {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
}

body {
    background: #e5e5e5;
    color: #222;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 17px;
    line-height: 1.6;
}

.page {
    width: 210mm;
    min-height: 297mm;
    margin: 15mm auto;
    padding: 20mm 25mm;
    background: white;
    box-shadow: 0 0 10px rgba(0,0,0,.22);
}

.screen-nav {
    margin: 0 0 20px;
    padding: 8px 0;
    text-align: center;
    font-size: 14px;
    border-bottom: 1px solid #ddd;
}

.screen-nav a {
    color: #245a8d;
    text-decoration: none;
    margin: 0 6px;
}

.screen-nav a:hover,
.screen-nav a:focus {
    text-decoration: underline;
}

h1 {
    margin: 0 0 24px;
    text-align: center;
    font-size: 21px;
    line-height: 1.3;
    font-weight: 600;
}

.introduction {
    margin: 0 auto 24px;
    text-align: center;
}

.phoneme {
    font-family: "Lucida Sans Unicode", "Arial Unicode MS", Arial, sans-serif;
}

.instructions {
    max-width: 650px;
    margin: 0 auto 28px;
    text-align: center;
}

.example {
    margin: 0 auto 30px;
    padding: 12px 18px;
    max-width: 600px;
    text-align: center;
    background: #f5f7f9;
    border: 1px solid #ddd;
}

.question-area {
    max-width: 650px;
    margin: 0 auto;
    text-align: center;
}

.question-number {
    margin-bottom: 12px;
    font-size: 16px;
    font-weight: bold;
}

.listen-button {
    display: block;
    margin: 0 auto 28px;
    padding: 12px 28px;
    min-width: 130px;
    border: 1px solid #245a8d;
    border-radius: 4px;
    background: #245a8d;
    color: white;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 17px;
    cursor: pointer;
}

.listen-button:hover,
.listen-button:focus {
    background: #1d496f;
}

.answer-buttons {
    display: flex;
    justify-content: center;
    gap: 35px;
    margin: 0 auto 24px;
}

.answer-button {
    min-width: 150px;
    padding: 13px 20px;
    border: 1px solid #888;
    border-radius: 4px;
    background: white;
    color: #222;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 19px;
    cursor: pointer;
}

.answer-button:hover,
.answer-button:focus {
    background: #f0f0f0;
}

.answer-button:disabled {
    cursor: default;
    opacity: 1;
}

.feedback {
    min-height: 54px;
    margin: 15px auto;
    font-size: 18px;
    font-weight: bold;
}

.next-button,
.restart-button {
    padding: 9px 20px;
    border: 1px solid #555;
    border-radius: 4px;
    background: #eee;
    color: #222;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 15px;
    cursor: pointer;
}

.next-button:hover,
.next-button:focus,
.restart-button:hover,
.restart-button:focus {
    background: #ddd;
}

.score {
    margin-top: 28px;
    font-size: 17px;
    font-weight: bold;
}

.final-message {
    margin: 20px auto;
    max-width: 600px;
    text-align: center;
    font-size: 19px;
}
.footer {
    margin-top: 24px;
    text-align: center;
    font-size: 13px;
}

.hidden {
    display: none !important;
}

@media (max-width: 800px) {
    body {
        background: white;
    }

    .page {
        width: 94%;
        min-height: auto;
        margin: 20px auto;
        padding: 24px 28px;
        box-shadow: none;
    }

    .answer-buttons {
        gap: 15px;
    }

    .answer-button {
        min-width: 120px;
    }
}

@media (max-width: 500px) {
    .answer-buttons {
        flex-direction: column;
        align-items: center;
        gap: 12px;
    }

    .answer-button {
        width: 80%;
    }
}

@media print {
    body {
        background: white;
        font-size: 12pt;
    }

    .page {
        width: 100%;
        min-height: 0;
        margin: 0;
        padding: 0;
        box-shadow: none;
    }

    .screen-nav,
    .listen-button,
    .next-button,
    .restart-button,
h1 {
        font-size: 18pt;
    }

    .footer {
        font-size: 9pt;
    }
}

.next-exercise {
    margin: 28px auto 0;
    padding-top: 18px;
    border-top: 1px solid #ddd;
    text-align: center;
    font-size: 15px;
}

.next-exercise a {
    color: #245a8d;
    text-decoration: none;
}

.next-exercise a:hover,
.next-exercise a:focus {
    text-decoration: underline;
}

@media print {
    .next-exercise {
        display: none;
    }
}
</style>
</head>

<body>

<div class="page">

    <div class="screen-nav">
    <a href="minimal-exercises.html">Minimal Pairs: Listening exercises</a> |<a href="minimal.html">Minimal Pairs</a> |
        <a href="phono.html">L1 pronunciation problems</a> |
        <a href="index.html">Home</a>
    </div>

    <h1>
        Minimal Pairs –
        <span class="phoneme">/k/</span> and
        <span class="phoneme">/g/</span>
    </h1>

    <p class="introduction">
        <span class="phoneme">/k/</span> as in <strong>"coal"</strong>
        &nbsp; · &nbsp;
        <span class="phoneme">/g/</span> as in <strong>"goal"</strong>
    </p>

    <p class="instructions">
        Listen to the word and choose the word you hear.
    </p>

    <div class="example">
        <strong>Example:</strong><br>
        Press <strong>Listen</strong>. You will hear one of the two words.
        Choose the word you hear.
    </div>

    <div class="question-area">

        <div id="quiz">

            <div class="question-number" id="questionNumber">
                Question 1 of 21
            </div>

            <button
                type="button"
                class="listen-button"
                id="listenButton">
                🔊 Listen
            </button>

            <div class="answer-buttons">

                <button
                    type="button"
                    class="answer-button"
                    id="answerA">
                    coal
                </button>

                <button
                    type="button"
                    class="answer-button"
                    id="answerB">
                    goal
                </button>

            </div>

            <div
                class="feedback"
                id="feedback"
                aria-live="polite">
            </div>

            <button
                type="button"
                class="next-button hidden"
                id="nextButton">
                Next question
            </button>

            <div class="score" id="score">
                Score: 0 / 21
            </div>

        </div>

        <div id="finalScreen" class="hidden">

            <div class="final-message" id="finalMessage"></div>

            <button
                type="button"
                class="restart-button"
                id="restartButton">
                Start again
            </button>

        </div>

    </div>

    <p class="instruction">
        Listen carefully to the difference between the two consonant sounds.
    </p>

    <div class="footer">
        Listening discrimination practice – British English consonant contrast
    </div>
<div class="next-exercise">
    <a href="minimal2728i.html">
        Next exercise: Listening Discrimination – /f/ and /v/ →
    </a>
</div>

</div>

<script>

const pairs = [
    ["coal", "goal"],
    ["coat", "goat"],
    ["course", "gorse"],
    ["cap", "gap"],
    ["come", "gum"],
    ["core", "gore"],
    ["kill", "gill"],
    ["curl", "girl"],
    ["Kate", "gate"],
    ["cold", "gold"],
    ["kilt", "guilt"],
    ["nickel", "niggle"],
    ["decree", "degree"],
    ["archive", "Argive"],
    ["bicker", "bigger"],
    ["picky", "piggy"],
    ["pick", "pig"],
    ["Dick", "dig"],
    ["lock", "log"],
    ["dock", "dog"],
    ["duck", "dug"]
];

let questions = [];
let currentQuestion = 0;
let score = 0;
let answered = false;

function shuffle(array) {
    const copy = array.slice();

    for (let i = copy.length - 1; i > 0; i--) {
        const j = Math.floor(Math.random() * (i + 1));
        [copy[i], copy[j]] = [copy[j], copy[i]];
    }

    return copy;
}

function createQuestions() {

    questions = shuffle(pairs).map(function(pair) {

        const heardIndex = Math.random() < 0.5 ? 0 : 1;

        return {
            first: pair[0],
            second: pair[1],
            heard: pair[heardIndex]
        };

    });
}

function speakWord() {

    if (!("speechSynthesis" in window)) {
        document.getElementById("feedback").textContent =
            "Speech synthesis is not available in this browser.";
        return;
    }

    window.speechSynthesis.cancel();

    const utterance = new SpeechSynthesisUtterance(
        questions[currentQuestion].heard
    );

    utterance.lang = "en-GB";
    utterance.rate = 0.82;
    utterance.pitch = 1;
    utterance.volume = 1;

    window.speechSynthesis.speak(utterance);
}

function showQuestion() {

    answered = false;

    const question = questions[currentQuestion];

    document.getElementById("questionNumber").textContent =
        "Question " + (currentQuestion + 1) + " of " + questions.length;

    document.getElementById("answerA").textContent = question.first;
    document.getElementById("answerB").textContent = question.second;

    document.getElementById("answerA").disabled = false;
    document.getElementById("answerB").disabled = false;

    document.getElementById("feedback").textContent = "";

    document.getElementById("nextButton").classList.add("hidden");

    document.getElementById("score").textContent =
        "Score: " + score + " / " + questions.length;

    setTimeout(function() {
        speakWord();
    }, 250);
}

function checkAnswer(selectedWord) {

    if (answered) {
        return;
    }

    answered = true;

    const correctWord = questions[currentQuestion].heard;

    document.getElementById("answerA").disabled = true;
    document.getElementById("answerB").disabled = true;

    if (selectedWord === correctWord) {

        score++;

        document.getElementById("feedback").textContent =
            "✓ Correct. You heard \"" + correctWord + "\".";

    } else {

        document.getElementById("feedback").textContent =
            "✗ Incorrect. The word was \"" + correctWord + "\".";
    }

    document.getElementById("score").textContent =
        "Score: " + score + " / " + questions.length;

    if (currentQuestion < questions.length - 1) {

        document.getElementById("nextButton").classList.remove("hidden");

    } else {

        showFinalScore();
    }
}

function nextQuestion() {

    currentQuestion++;

    if (currentQuestion < questions.length) {
        showQuestion();
    }
}

function showFinalScore() {

    document.getElementById("quiz").classList.add("hidden");

    document.getElementById("finalScreen").classList.remove("hidden");

    document.getElementById("finalMessage").innerHTML =
        "<strong>You have completed the exercise.</strong><br><br>" +
        "Your score is <strong>" +
        score +
        " / " +
        questions.length +
        "</strong>.";
}

function restartExercise() {

    window.speechSynthesis.cancel();

    currentQuestion = 0;
    score = 0;

    createQuestions();

    document.getElementById("quiz").classList.remove("hidden");
    document.getElementById("finalScreen").classList.add("hidden");

    showQuestion();
}

document.getElementById("listenButton").addEventListener(
    "click",
    speakWord
);

document.getElementById("answerA").addEventListener(
    "click",
    function() {
        checkAnswer(this.textContent);
    }
);

document.getElementById("answerB").addEventListener(
    "click",
    function() {
        checkAnswer(this.textContent);
    }
);

document.getElementById("nextButton").addEventListener(
    "click",
    nextQuestion
);

document.getElementById("restartButton").addEventListener(
    "click",
    restartExercise
);

createQuestions();
showQuestion();

</script>

</body>
</html>
```