Greasy Fork is available in English.

Show English and Chinese Subtitles for Coursera

Show English and Chinese subtitles when you're watching coursera, and you may modify the script mannually as you like

// ==UserScript==
// @name         Show English and Chinese Subtitles for Coursera
// @name:zh      于 Coursera 显示中英双字幕
// @name:zh-CN   于 Coursera 显示中英双字幕
// @name:zh-TW   于 Coursera 顯示中英雙字
// @namespace    http://tampermonkey.net/
// @version      0.3
// @description         Show English and Chinese subtitles when you're watching coursera, and you may modify the script mannually as you like
// @description:zh      在 Coursera 显示中英双字幕或手动更改脚本来更换其它语言
// @description:zh-CN   在 Coursera 显示中英双字幕或手动更改脚本来更换其他语言
// @description:zh-TW   于 Coursera 顯示中英雙字或手動更改脚本來更換其他語言
// @author       LouizQ
// @include      http://www.coursera.org/*
// @include      https://www.coursera.org/*
// @grant        none
// @run-at       document-end
// ==/UserScript==

(function() {
    'use strict';

    //==========================================================================================================
    //If you're using high dpi screen, we strongly advise you to add the script:
    //若为高分辨率屏幕，我们强烈建议您使用：
    //若為高分辨率屏幕，我們强烈建議您使用：

    //https://greasyfork.org/scripts/32934-smaller-coursera-subtitle/code/Smaller%20Coursera%20Subtitle.user.js

    //or uncomment following stript part to reduce size of coursera subtitle
    //或手动取消下面这段脚本的注释，以缩小字幕字号
    //或手動取消下面這段脚本的注釋，以縮小字幕字號

    /*
    var css = 'video::-webkit-media-text-track-display {font-size: 45%;}',
        head = document.head || document.getElementsByTagName('head')[0],
        style = document.createElement('style');
    style.type = 'text/css';
    if (style.styleSheet){
        style.styleSheet.cssText = css;
    } else {
        style.appendChild(document.createTextNode(css));
    }
    head.appendChild(style);
    */
    //==========================================================================================================

    setInterval(function(){
        var video = document.getElementById("c-video_html5_api");
        if(video){
            var n = video.textTracks;
            var bsubtitleoff = true;
            for (var o = 0; o < n.length; o++) {
                var i = n[o];
                if (i.kind !== "subtitles") continue;
                if (i.mode == "showing") bsubtitleoff = false;
            }
            if (!bsubtitleoff) {
                for (var o = 0; o < n.length; o++) {
                    var i = n[o];
                    //console.log(i.language);
                    /*
                    you may delete the double slash above (uncomment it), click save, and refresh coursera webpage to see the language list in console(F12).
                    你可以删除前一句双斜杠的注释符号，保存并刷新，在控制台（console，F12）中查看有哪些语言。
                    你可以刪除前一句雙斜杠的注釋符號，保存並刷新，在控制臺（console，F12）中查看有哪些語言。
                    */
                    if (i.kind !== "subtitles") continue;
                    if (i.language == "zh-CN" || i.language == "zh-TW" || i.language == "en-US" || i.language == "en") {
                        /*
                        if you want to change the fixed language, just modify the word in quotation mark as you like
                        如果你希望更换语言，可以手动修改引号中的内容
                        如果你希望更換語言，可以手動修改引號中的内容
                        */
                        i.mode = "showing";
                    } else {
                        i.mode = "hidden";
                    }
                }
            } else {
                //warning: you didn't allow to show any subtitles
                //字幕未开启//字幕未開啓
            }
        }
    },500);
})();