diff --git a/chapters/hmm/hmm_filter.ipynb b/chapters/hmm/hmm_filter.ipynb
index 1e779e9..413d7a0 100644
--- a/chapters/hmm/hmm_filter.ipynb
+++ b/chapters/hmm/hmm_filter.ipynb
@@ -141,7 +141,7 @@
    "source": [
     "\n",
     "Since all the quantities are finite length vectors and matrices,\n",
-    "we can implement the whole procedure using matrix vector multoplication:\n",
+    "we can implement the whole procedure using matrix vector multiplication:\n",
     "```{math}\n",
     ":label: eqn:fwdsAlgoMatrixForm\n",
     "\\valpha_t =\\text{normalize}\\left(\n",
@@ -278,7 +278,7 @@
     "\n",
     "In practice it is more numerically stable to compute\n",
     "the log likelihoods $\\ell_t(j) = \\log p(\\obs_t|\\hidden_t=j)$,\n",
-    "rather than the likelioods $\\lambda_t(j) = p(\\obs_t|\\hidden_t=j)$.\n",
+    "rather than the likelihoods $\\lambda_t(j) = p(\\obs_t|\\hidden_t=j)$.\n",
     "In this case, we can perform the posterior updating in a numerically stable way as follows.\n",
     "Define $L_t = \\max_j \\ell_t(j)$ and\n",
     "\\begin{align}\n",
diff --git a/chapters/ssm/hmm.ipynb b/chapters/ssm/hmm.ipynb
index 70648ae..fc7f4b2 100644
--- a/chapters/ssm/hmm.ipynb
+++ b/chapters/ssm/hmm.ipynb
@@ -80,7 +80,7 @@
     "### Example: Casino HMM\n",
     "\n",
     "To illustrate HMMs with categorical observation model,\n",
-    "we consider the \"Ocassionally dishonest casino\" model from {cite}`Durbin98`.\n",
+    "we consider the \"Occasionally dishonest casino\" model from {cite}`Durbin98`.\n",
     "There are 2 hidden states, representing whether the dice being used in the casino is fair or loaded.\n",
     "Each state defines a distribution over the 6 possible observations.\n",
     "\n",
@@ -241,7 +241,7 @@
     "Let us check correctness by computing empirical pairwise statistics\n",
     "\n",
     "We will compute the number of i->j latent state transitions, and check that it is close to the true \n",
-    "A[i,j] transition probabilites."
+    "A[i,j] transition probabilities."
    ]
   },
   {