diff --git a/units/en/unit1/hands-on.mdx b/units/en/unit1/hands-on.mdx
index c8a1b8e..b777055 100644
--- a/units/en/unit1/hands-on.mdx
+++ b/units/en/unit1/hands-on.mdx
@@ -12,6 +12,6 @@ Thanks to our <a href="https://huggingface.co/spaces/huggingface-projects/Deep-R
 
 So let's get started! 🚀
 
-To start the hands-on click on Open In Colab button 👇 :
+**To start the hands-on click on Open In Colab button** 👇 :
 
 [![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)]()
diff --git a/units/en/unit1/quiz.mdx b/units/en/unit1/quiz.mdx
index 3ccf3ca..5dece14 100644
--- a/units/en/unit1/quiz.mdx
+++ b/units/en/unit1/quiz.mdx
@@ -1,6 +1,6 @@
 # Quiz [[quiz]]
 
-The best way to learn and [to avoid the illusion of competence](https://fr.coursera.org/lecture/learning-how-to-learn/illusions-of-competence-BuFzf) **is to test yourself.** This will help you to find **where you need to reinforce your knowledge**.
+The best way to learn and [to avoid the illusion of competence](https://www.coursera.org/lecture/learning-how-to-learn/illusions-of-competence-BuFzf) **is to test yourself.** This will help you to find **where you need to reinforce your knowledge**.
 
 ### Q1: What is Reinforcement Learning?
 
diff --git a/units/en/unit1/rl-framework.mdx b/units/en/unit1/rl-framework.mdx
index 7aae384..b6a01a1 100644
--- a/units/en/unit1/rl-framework.mdx
+++ b/units/en/unit1/rl-framework.mdx
@@ -108,7 +108,7 @@ Taking this information into consideration is crucial because it will **have im
 
 The reward is fundamental in RL because it’s **the only feedback** for the agent. Thanks to it, our agent knows **if the action taken was good or not.**
 
-The cumulative reward at each time step t can be written as:
+The cumulative reward at each time step **t** can be written as:
 
 <figure>
 <img src="https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/unit1/rewards_1.jpg" alt="Rewards">
diff --git a/units/en/unit2/quiz1.mdx b/units/en/unit2/quiz1.mdx
index 54ba038..cc5692d 100644
--- a/units/en/unit2/quiz1.mdx
+++ b/units/en/unit2/quiz1.mdx
@@ -1,6 +1,6 @@
 # First Quiz [[quiz1]]
 
-The best way to learn and [to avoid the illusion of competence](https://fr.coursera.org/lecture/learning-how-to-learn/illusions-of-competence-BuFzf) **is to test yourself.** This will help you to find **where you need to reinforce your knowledge**.
+The best way to learn and [to avoid the illusion of competence](https://www.coursera.org/lecture/learning-how-to-learn/illusions-of-competence-BuFzf) **is to test yourself.** This will help you to find **where you need to reinforce your knowledge**.
 
 
 ### Q1: What are the two main approaches to find optimal policy?
diff --git a/units/en/unit2/quiz2.mdx b/units/en/unit2/quiz2.mdx
index 73fe187..9d96d74 100644
--- a/units/en/unit2/quiz2.mdx
+++ b/units/en/unit2/quiz2.mdx
@@ -1,6 +1,6 @@
 # Second Quiz [[quiz2]]
 
-The best way to learn and [to avoid the illusion of competence](https://fr.coursera.org/lecture/learning-how-to-learn/illusions-of-competence-BuFzf) **is to test yourself.** This will help you to find **where you need to reinforce your knowledge**.
+The best way to learn and [to avoid the illusion of competence](https://www.coursera.org/lecture/learning-how-to-learn/illusions-of-competence-BuFzf) **is to test yourself.** This will help you to find **where you need to reinforce your knowledge**.
 
 
 ### Q1: What is Q-Learning?
diff --git a/units/en/unit3/quiz.mdx b/units/en/unit3/quiz.mdx
index bde7e78..cefffa6 100644
--- a/units/en/unit3/quiz.mdx
+++ b/units/en/unit3/quiz.mdx
@@ -1,6 +1,6 @@
 # Quiz [[quiz]]
 
-The best way to learn and [to avoid the illusion of competence](https://fr.coursera.org/lecture/learning-how-to-learn/illusions-of-competence-BuFzf) **is to test yourself.** This will help you to find **where you need to reinforce your knowledge**.
+The best way to learn and [to avoid the illusion of competence](https://www.coursera.org/lecture/learning-how-to-learn/illusions-of-competence-BuFzf) **is to test yourself.** This will help you to find **where you need to reinforce your knowledge**.
 
 ### Q1: What are tabular methods?