diff --git a/chapters/02/3/establishing-causality.md b/chapters/02/3/establishing-causality.md
index 74c0ce544..394dd6d44 100644
--- a/chapters/02/3/establishing-causality.md
+++ b/chapters/02/3/establishing-causality.md
@@ -2,7 +2,7 @@ Establishing Causality
 ======================
 
 In the language developed earlier in the section, you can think of the people in
-the S&V houses as the treatment group, and those in the Lambeth houses at the
+the S&V houses as the treatment group, and those in the Lambeth houses as the
 control group. A crucial element in Snow’s analysis was that the people in the
 two groups were comparable to each other, apart from the treatment.
 
diff --git a/chapters/02/4/randomization.md b/chapters/02/4/randomization.md
index 7e76ada32..71755f298 100644
--- a/chapters/02/4/randomization.md
+++ b/chapters/02/4/randomization.md
@@ -22,7 +22,7 @@ becoming more commonly used in other fields such as economics.
 **Example: Welfare subsidies in Mexico.** In Mexican villages in the 1990’s,
 children in poor families were often not enrolled in school. One of the reasons
 was that the older children could go to work and thus help support the family.
-Santiago Levy , a minister in Mexican Ministry of Finance, set out to
+Santiago Levy, a minister in Mexican Ministry of Finance, set out to
 investigate whether welfare programs could be used to increase school enrollment
 and improve health conditions. He conducted an RCT on a set of villages,
 selecting some of them at random to receive a new welfare program called
diff --git a/chapters/03/1/Expressions.ipynb b/chapters/03/1/Expressions.ipynb
index 7d583b536..b80372ece 100644
--- a/chapters/03/1/Expressions.ipynb
+++ b/chapters/03/1/Expressions.ipynb
@@ -91,7 +91,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "**Common Operators.** Data science often involves combining numerical values, and the set of operators in a programming language are designed to so that expressions can be used to express any sort of arithmetic. In Python, the following operators are essential.\n",
+    "**Common Operators.** Data science often involves combining numerical values, and the set of operators in a programming language are designed so that expressions can be used to express any sort of arithmetic. In Python, the following operators are essential.\n",
     "\n",
     "| Expression Type | Operator | Example    | Value     |\n",
     "|-----------------|----------|------------|-----------|\n",