<?php
// See https://wordpress.stackexchange.com/a/306993/137402 for details.

add_action( 'init', 'my_register_questions_post_types' );
function my_register_questions_post_types() {
    register_post_type( 'english-speaking', array(
        'label' => 'English Speaking',
        'public' => true,
        'supports' => [ 'title', 'editor', 'custom-fields' ],
        'rewrite' => array(
            'slug' => 'english/speaking/%speaking_task%/%question_id%',
        ),
        // Other args here.
    ) );

    register_post_type( 'english-writing', array(
        'label' => 'English Writing',
        'public' => true,
        'supports' => [ 'title', 'editor', 'custom-fields' ],
        'rewrite' => array(
            'slug' => 'english/writing/%question_id%',
        ),
        // Other args here.
    ) );
}

add_action( 'init', 'my_register_questions_taxonomies' );
function my_register_questions_taxonomies() {
    register_taxonomy( 'speaking-task', array( 'english-speaking' ), array(
        'label' => 'Speaking Tasks',
        'public' => true,
        'hierarchical' => true,
        'rewrite' => array(
            'slug' => 'english/speaking',
        ),
        // Other args here.
    ) );
}

add_action( 'init', 'my_register_questions_rewrite_tags' );
function my_register_questions_rewrite_tags() {
    add_rewrite_tag( '%question_id%', '(\d+)' );
    add_rewrite_tag( '%speaking_task%', '([^/]+)' );
}

add_filter( 'post_type_link', 'my_filter_questions_post_type_link', 10, 2 );
function my_filter_questions_post_type_link( $post_link, $post ) {
    // Replaces/rewrites %question_id% in the permalink.
    if ( false !== strpos( $post_link, '%question_id%' ) ) {
        $id = get_post_meta( $post->ID, 'wpcf-question-id', true );

        // A default value is necessary, and the value has to be a 0.
        $id = $id ? $id : '0';

        $post_link = str_replace( '%question_id%', $id, $post_link );
    }

    // Replaces/rewrites %speaking_task% in the permalink.
    if ( false !== strpos( $post_link, '%speaking_task%' ) ) {
        // A default value is necessary, but the term/category doesn't need to
        // actually exists. So you could, for example, use 'all' as the value.
        $slug = 'uncategorized';

        $cats = get_the_terms( $post, 'speaking-task' );
        if ( $cats && ! is_wp_error( $cats ) ) {
            $slug = $cats[0]->slug;
        }

        $post_link = str_replace( '%speaking_task%', $slug, $post_link );
    }

    return $post_link;
}