diff --git a/docs/.vitepress/theme/components/TTS.vue b/docs/.vitepress/theme/components/TTS.vue
index ba7c24f..1276811 100644
--- a/docs/.vitepress/theme/components/TTS.vue
+++ b/docs/.vitepress/theme/components/TTS.vue
@@ -3,7 +3,11 @@
     <span ref="main" :class="class" :lang="lang">
       <slot />
     </span>
-    <audio style="display: none" ref="audio"></audio>
+    <audio
+      style="display: none"
+      ref="audio"
+      @error="playAudioTTSPlugin()"
+    ></audio>
     <span>
       <button type="button" @click="playAudio()" :class="$style.speak">
         🗣️
@@ -80,7 +84,6 @@ async function playAudioTTSPlugin(): Promise<boolean> {
 
 <style module>
 .speak {
-  text-align: center;
-  width: 2em;
+  margin-inline-start: 0.2em;
 }
 </style>
diff --git a/docs/howtostudykorean/unit-1/12-more-particles.md b/docs/howtostudykorean/unit-1/12-more-particles.md
index 8b2b757..fd948d6 100644
--- a/docs/howtostudykorean/unit-1/12-more-particles.md
+++ b/docs/howtostudykorean/unit-1/12-more-particles.md
@@ -604,6 +604,210 @@ sentence:
     - ko: 저는 그 여자를 **그때만** 사랑했어요
       audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-9.mp3
       en: I loved her **only at that time**
+      notes: When using 그때, ~에 is often omitted because it can be assumed.
+
+  에서:
+    - ko: 저는 학교**에서** 공부할 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-26.mp3
+      en: I will study **at** school
+    - ko: 저는 저의 친구를 병원**에서** 봤어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-27.mp3
+      en: I saw my friend **at** the hospital
+    - ko: 저는 남편을 공원**에서** 만날 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-28.mp3
+      en: I will meet my husband **at** the park
+    - ko: 저는 한국어를 한국**에서** 배웠어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-29.mp3
+      en: I learned Korean **in** Korea
+
+    - ko: 저는 방**에서** 탁자에 병을 놓았어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-10.mp3
+      en: I placed the bottle on the table **in** the room
+
+    - ko: 저는 한국**에서** 갈 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/11/Lesson-12-s3.mp3
+      en: the person left **from** Korea
+      notes: (This sentence is correct, but it is stating that the person left from Korea because the action of “going” (가다) is <span class="md spoiler">occurring at/in Korea</span>)
+
+    - ko: 과일은 비싸요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-11.mp3
+      en: Fruit is expensive
+    - ko: 과일은 한국**에서** 비싸요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-12.mp3
+      en: Fruit is expensive **in** Korea
+
+    - ko: 저는 학교**에서** 추웠어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-13.mp3
+      en: I was cold **at** school
+    - ko: 고등학교는 한국**에서** 어려워요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-14.mp3
+      en: High school is difficult **in** Korea
+    - ko: 녹차는 한국**에서** 유명해요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-15.mp3
+      en: Green Tea is famous **in** Korea
+
+    - ko: 저는 집**에** 있어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-16.mp3
+      en: I’m **at** home
+      notes: when you indicate where something is by using 있다, you should use ~에 instead of ~에서
+    - ko: 저는 차 안**에** 있어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-17.mp3
+      en: I’m **in** the car
+      notes: when you indicate where something is by using 있다, you should use ~에 instead of ~에서
+
+    - ko: 저는 한국**에서** 갈 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/11/Lesson-12-s3.mp3
+      en: I will go **from** Korea
+      notes: it can be used to indicate the place from which the subject is departing.
+    - ko: 다음 버스는 저 정류장**에서** 출발할 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-39.mp3
+      en: The next bus will depart **from** that station
+      notes: it can be used to indicate the place from which the subject is departing.
+
+    - ko: 저는 서울역**에서** 내릴 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-40.mp3
+      en: I will get off **at (from)** Seoul station
+      notes: When you are getting off of something (bus/train)
+
+    - ko: 학생은 교실**에서** 나왔어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-41.mp3
+      en: the student came **out of** the classroom
+      notes: When something/someone is coming/going/being taken out of something
+
+    - ko: 저는 캐나다**에서** 왔어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-18.mp3
+      en: I come **from** Canada
+      notes: You can also use this to indicate the country (or any other place, for that matter) that you come from.
+
+  까지:
+    - ko: 3시**까지** 기다릴 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-43.mp3
+      en: I will wait **until** 3:00
+    - ko: 그 여자를 지금**까지** 좋아했어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-44.mp3
+      en: I liked that girl **until** now
+    - ko: 저는 그 회사에서 5월**까지** 일할 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-45.mp3
+      en: I will work at that company **until** May
+    - ko: 저는 그때**까지** 김치를 먹지 않았어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-19.mp3
+      en: I hadn’t eaten Kimchi **until** that time
+    - ko: 저는 오늘 이 책을 여기**까지** 읽었어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-20.mp3
+      en: Today, I read **up to** here in this book
+    - ko: 저는 한강**까지** 달렸어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-21.mp3
+      en: I ran **until** (I **reached**) the Han River
+
+  부터:
+    - ko: 나는 인천**에서** 서울**까지** 갈 거야
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-22.mp3
+      en: I will depart **from** Incheon and go **to (until)** Seoul
+    - ko: 나는 인천**부터** 서울**까지** 갈 거야
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-50.mp3
+      en: I will go **from** Incheon **to** Seoul
+
+    - ko: 다음 버스는 저 정류장**에서** 출발할 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-39.mp3
+      en: The next bus will depart **from** that station
+
+    - ko: 저는 어제**부터** 아팠어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-23.mp3
+      en: I have been sick **since (from)** yesterday
+    - ko: 저는 내일**부터** 한국어를 공부할 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-24.mp3
+      en: I’m going to study Korean **from** tomorrow
+    - ko: 내년**부터** 우리는 서울에서 살 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-25.mp3
+      en: "**From** next year, we will be living in Seoul"
+    - ko: 저는 3시**부터** 학교에 있을 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-26.mp3
+      en: I will be at school **from** 3:00
+    - ko: 저는 작년**부터** 한국어를 배웠어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-27.mp3
+      en: I have been learning Korean **since** last year
+
+    - ko: 저는 아침**부터** 밤**까지** 공부만 했어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-57.mp3
+      en: "**From** morning **to** night I only studied"
+    - ko: 나는 캐나다에 1일**부터** 8일**까지** 있을 거야
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-58.mp3
+      en: I will be in Canada **from** the 1st **to** the 8th
+
+    - ko: 그들은 저를 **처음부터** 싫어했어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-28.mp3
+      en: They didn’t like me **from the start**
+    - ko: 우리는 그 일을 **처음부터** 시작할 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-29.mp3
+      en: We will start that job/task **from the beginning**
+
+    - ko: 저는 그 상황을 **처음부터 끝까지** 몰랐어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-30.mp3
+      en: I didn’t know that situation **from start to finish**
+    - ko: 저는 그것을 **처음부터 끝까지** 복습했어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-31.mp3
+      en: I reviewed that **from start to finish**
+    - ko: 저는 그 책을 **처음부터 끝까지** 읽었어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-32.mp3
+      en: I read that book **from start to finish**
+
+  로:
+    - ko: 나는 우리 집을 나무**로** 지었어
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-64.mp3
+      en: I built our house **out of** wood
+    - ko: 배**로** 제주에 갈 거야
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-65.mp3
+      en: I will go to Je-ju **by** boat
+    - ko: 저는 그것을 손**으로** 만들었어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-66.mp3
+      en: I built that **with** my hands
+
+    - ko: 저는 그 문장을 한국어**로** 말했어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-33.mp3
+      en: I said that sentence **(using) in** Korean
+    - ko: 저는 그것**을** 영어로 할 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-34.mp3
+      en: I will say that (**using**) in English
+
+    - ko: 저는 아침식사**로** 밥을 먹었어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-69.mp3
+      en: I ate rice **for** breakfast
+    - ko: 저는 보통 점심식사**로** 과일만 먹었어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-70.mp3
+      en: I usually only ate fruit **for** lunch
+
+    - ko: 저는 그것을 두 번째**로** 했어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-35.mp3
+      en: I did that second (I was the second person to do that)
+    - ko: 저는 학교에 두 번째**로** 왔어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-36.mp3
+      en: I came **to** school second (I was the second person to come **to** school)
+    - ko: 저는 그것을 첫 번째**로** 할 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-37.mp3
+      en: I will go **(do it)** first
+
+    - ko: 저는 집**으로** 갈 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-74.mp3
+      en: I will go **in** the direction of home (simply ‘I will go home’)
+    - ko: 저는 집**에** 갈 거예요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/11/Lesson-12-s4.mp3
+      en: I will go home
+
+    - ko: 저의 친구는 저 쪽**으로** 갔어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-76.mp3
+      en: My friend went that way
+    - ko: 학생들은 교실 쪽**으로** 걸어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2017/03/Lesson12-77.mp3"
+      en: Students walk **towards/in** the direction of their class
+
+    - ko: 저는 집 안 쪽**으로** 달렸어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-38.mp3
+      en: I ran **inside** the house
+      notes: In the first example, you are running into the house/in the direction of ‘inside the house.’
+    - ko: 저는 집 안**에서** 달렸어요
+      audio: https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-39.mp3
+      en: I ran **inside** the house
+      notes: In the second example, you are running inside the house.
 ---
 
 # Lesson 12: Korean Particles 들, 만, 에서, 부터, 까지, (으)로
@@ -1516,7 +1720,7 @@ I’ll show now how it can be attached to the ~에 particle we’ve covered, and
 - 저는 커피를 낮에만 마셔요 <AudioButton src="https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-8.mp3" /> = <span class="md spoiler">I drink coffee only during the day</span>
 - 저는 그 여자를 그때만 사랑했어요 <AudioButton src="https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-9.mp3" /> = <span class="md spoiler">I loved her only at that time</span>
 
-_When using_ 그때*,* ~에 _is often omitted because it can be assumed._
+_When using 그때, ~에 is often omitted because it can be assumed._
 
 [You can see ~만 used on a Korean sign in this YouTube video.]
 
@@ -1524,6 +1728,8 @@ _When using_ 그때*,* ~에 _is often omitted because it can be assumed._
 
 ## Korean Particle ~에서
 
+<VocabQuiz fm-key="sentence" category="에서" />
+
 Foreign learners of Korean are often very confused as to when they should use ~에서 instead of ~에, as they both denote places in Korean sentences. ~에서 is used to denote the location in which the subject is doing something.
 
 For example:
@@ -1652,6 +1858,8 @@ As you can see, ‘from’ (in English) has many usages as well. When a word has
 
 ## Korean Particles ~부터 and ~까지
 
+<VocabQuiz fm-key="sentence" category="까지" />
+
 Two more important Korean particles you need to know are ~부터 and ~까지.
 
 ~까지 can be used in sentences with or without ~에서 to have the meaning of “to/until a place/time.” For example:
@@ -1667,6 +1875,8 @@ Two more important Korean particles you need to know are ~부터 and ~까지.
 
 - 우리는 집에서 출발할 거예요 = <span class="md spoiler">We will depart from home</span>
 
+<VocabQuiz fm-key="sentence" category="부터" />
+
 ~부터 is very similar, but is specifically identifying the place (or time) in which something _starts_ from. If we look at this sentence:
 
 - 나는 인천에서 서울까지 갈 거야 <AudioButton src="https://www.howtostudykorean.com/wp-content/uploads/2015/02/Lesson-12-sentence-22.mp3" /> = <span class="md spoiler">I will depart from Incheon and go to (until) Seoul</span>
@@ -1712,6 +1922,8 @@ When used to say “from start to finish,” the word “<TTS>끝</TTS>” is of
 
 ## Korean Particle ~(으)로
 
+<VocabQuiz fm-key="sentence" category="로" />
+
 The Korean particle ~(으)로 can be added to nouns with a few different meanings. One of the main meanings is to indicate with what tool/device/method/material something is carried out. The English equivalent varies depending on the usage:
 
 - Write **with** a pen
@@ -1787,7 +1999,7 @@ In the first example, you are running into the house/in the direction of ‘insi
 
 That’s it for this lesson! I wanted to cover a few more particles, but this lesson already has way too much in it! In the next lesson, I will introduce you to more of these common particles. Until then, make sure you review this lesson before you move on!
 
-[Okay, I got it! Take me to the next lesson!](https://www.howtostudykorean.com/?page_id=965) Or,
+[Okay, I got it! Take me to the next lesson!](./13-and-with.md) Or,
 [Click here for a workbook to go along with this lesson.](https://www.howtostudykorean.com/workbooks#Unit1916)
 
 <em>There are 1250 example sentences in Unit 1.