diff --git a/src/pages/applicatives/applicative.md b/src/pages/applicatives/applicative.md
index 3976df38..648d6938 100644
--- a/src/pages/applicatives/applicative.md
+++ b/src/pages/applicatives/applicative.md
@@ -42,7 +42,7 @@ The `product` method from `Semigroupal`
 is defined in terms of `ap` and `map`.
 
 Don't worry too much about the implementation of `product`---it's
-difficult to read and the details aren't particuarly important.
+difficult to read and the details aren't particularly important.
 The main point is that there is a tight relationship
 between `product`, `ap`, and `map`
 that allows any one of them to be defined
diff --git a/src/pages/applicatives/parallel.md b/src/pages/applicatives/parallel.md
index 8089891f..17e7d59f 100644
--- a/src/pages/applicatives/parallel.md
+++ b/src/pages/applicatives/parallel.md
@@ -1,7 +1,7 @@
 ## Parallel
 
 In the previous section we saw that
-when call `product` on a type that
+when we call `product` on a type that
 has a `Monad` instance
 we get sequential semantics.
 This makes sense from the point-of-view
@@ -132,7 +132,7 @@ As the type parameter `A` is generic a `FunctionK` cannot inspect
 any values contained with the type constructor `M`.
 The conversion must be performed
 purely in terms of the structure of the type constructors `M` and `F`.
-We can in `optionToList` above
+We can see in `optionToList` above
 this is indeed the case.
 
 So in summary,
@@ -155,7 +155,7 @@ Does `List` have a `Parallel` instance? If so, what does the `Parallel` instance
 <div class="solution">
 `List` does have a `Parallel` instance, 
 and it zips the `List`
-insted of creating the cartesian product.
+instead of creating the cartesian product.
 
 We can see by writing a little bit of code.
 
diff --git a/src/pages/case-studies/crdt/g-counter.md b/src/pages/case-studies/crdt/g-counter.md
index 6d413517..f35ae598 100644
--- a/src/pages/case-studies/crdt/g-counter.md
+++ b/src/pages/case-studies/crdt/g-counter.md
@@ -101,7 +101,7 @@ where we represent machine IDs as `Strings`.
 
 ```scala mdoc:reset-object:silent
 final case class GCounter(counters: Map[String, Int]) {
-  def increment(machine: String, amount: Int) =
+  def increment(machine: String, amount: Int): GCounter =
     ???
 
   def merge(that: GCounter): GCounter =
diff --git a/src/pages/foldable-traverse/foldable-cats.md b/src/pages/foldable-traverse/foldable-cats.md
index 2116e54c..f596c2f7 100644
--- a/src/pages/foldable-traverse/foldable-cats.md
+++ b/src/pages/foldable-traverse/foldable-cats.md
@@ -100,7 +100,7 @@ provide stack safe implementations of `foldRight`:
 (1 to 100000).toVector.foldRight(0L)(_ + _)
 ```
 
-We've called out `Stream` because it is an exception to this rule.
+We've called out `LazyList` because it is an exception to this rule.
 Whatever data type we're using, though,
 it's useful to know that `Eval` has our back.
 </div>
diff --git a/src/pages/foldable-traverse/foldable.md b/src/pages/foldable-traverse/foldable.md
index 576aef44..03479a28 100644
--- a/src/pages/foldable-traverse/foldable.md
+++ b/src/pages/foldable-traverse/foldable.md
@@ -1,7 +1,7 @@
 ## Foldable {#sec:foldable}
 
 The `Foldable` type class captures the `foldLeft` and `foldRight` methods
-we're used to in sequences like `Lists`, `Vectors`, and `Streams`.
+we're used to in sequences like `Lists`, `Vectors`, and `LazyLists`.
 Using `Foldable`, we can write generic folds that work with a variety of sequence types.
 We can also invent new sequences and plug them into our code.
 `Foldable` gives us great use cases for `Monoids` and the `Eval` monad.
diff --git a/src/pages/foldable-traverse/traverse-cats.md b/src/pages/foldable-traverse/traverse-cats.md
index b4a78c72..dbd40f06 100644
--- a/src/pages/foldable-traverse/traverse-cats.md
+++ b/src/pages/foldable-traverse/traverse-cats.md
@@ -21,7 +21,7 @@ trait Traverse[F[_]] {
 ```
 
 Cats provides instances of `Traverse`
-for `List`, `Vector`, `Stream`, `Option`, `Either`,
+for `List`, `Vector`, `LazyList`, `Option`, `Either`,
 and a variety of other types.
 We can summon instances as usual using `Traverse.apply`
 and use the `traverse` and `sequence` methods
diff --git a/src/pages/foldable-traverse/traverse.md b/src/pages/foldable-traverse/traverse.md
index 500abc1d..b2146406 100644
--- a/src/pages/foldable-traverse/traverse.md
+++ b/src/pages/foldable-traverse/traverse.md
@@ -84,7 +84,7 @@ Await.result(allUptimes, 1.second)
 ```
 
 This is much clearer and more concise---let's see how it works.
-If we ignore distractions like `CanBuildFrom` and `ExecutionContext`,
+If we ignore distractions like `BuildFrom` and `ExecutionContext`,
 the implementation of `Future.traverse` in the standard library looks like this:
 
 ```scala