diff --git a/CM3060 Natural Language Processing/Week 3/2.2.1 Sentence segmentation.ipynb b/CM3060 Natural Language Processing/Week 3/2.2.1 Sentence segmentation.ipynb
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+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "id": "1878fa45-3b4a-44f5-b5fa-97c00adb4593",
+   "metadata": {},
+   "source": [
+    "# Sentence segmentation"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "id": "aff71edc-bb8f-49dc-a4fd-bbac1a74ebed",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import nltk"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "3708c40d-cb73-4a6e-96ad-6d6e70c862ff",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "[nltk_data] Downloading package punkt to C:\\nltk_data...\n",
+      "[nltk_data]   Package punkt is already up-to-date!\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "True"
+      ]
+     },
+     "execution_count": 2,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "nltk.download('punkt')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "id": "bd55a5f7-ff62-47b8-928b-d5b60b92e9f2",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "text = '''Punctuation denotes the end of a sentence!\n",
+    "“But not always!”, said Fred... (who is a professor).\n",
+    "Some sentences could break over multiple lines\n",
+    "and begin with a lower case letter.\n",
+    "a1 could be a variable name.\n",
+    "'''"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "id": "5fd18291-2765-4841-9cdf-4efbe110bded",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'Punctuation denotes the end of a sentence!\\n“But not always!”, said Fred... (who is a professor).\\nSome sentences could break over multiple lines\\nand begin with a lower case letter.\\na1 could be a variable name.\\n'"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "text"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "id": "2a010ec4-c5ad-4429-be04-7f3626d3a6e2",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "sents = nltk.sent_tokenize(text)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "74e585c9-a137-4008-824d-699dcb470943",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "'“But not always!”, said Fred... (who is a professor).'"
+      ]
+     },
+     "execution_count": 6,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "sents[1]"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "id": "815c6f21-4c1f-491a-96cf-b6ba6878eb67",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "4"
+      ]
+     },
+     "execution_count": 7,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "len(sents)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "id": "6c895aea-7fc0-47f0-a9ca-6710735da51a",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Punctuation denotes the end of a sentence!\n",
+      "“But not always!”, said Fred... (who is a professor).\n",
+      "Some sentences could break over multiple lines\n",
+      "and begin with a lower case letter.\n",
+      "a1 could be a variable name.\n"
+     ]
+    }
+   ],
+   "source": [
+    "for s in sents:\n",
+    "    print(s)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "id": "82da27f5-4ad0-4ec5-a20f-e83646a60fc4",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Punctuation denotes the end of a sentence!\n",
+      "---\n",
+      "“But not always!”, said Fred... (who is a professor).\n",
+      "---\n",
+      "Some sentences could break over multiple lines\n",
+      "and begin with a lower case letter.\n",
+      "---\n",
+      "a1 could be a variable name.\n"
+     ]
+    }
+   ],
+   "source": [
+    "print('\\n---\\n'.join(sents))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "id": "aecb0078-42ae-432a-8fc5-3f1cd9baa5db",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "4\n",
+      "\n",
+      "Punctuation denotes the end of a sentence!\n",
+      "“But not always!”, said Fred... (who is a professor).\n",
+      "Some sentences could break over multiple lines\n",
+      "and begin with a lower case letter.\n",
+      "a1 could be a variable name.\n"
+     ]
+    }
+   ],
+   "source": [
+    "text = '''Punctuation denotes the end of a sentence!\n",
+    "“But not always!”, said Fred... (who is a professor).\n",
+    "Some sentences could break over multiple lines\n",
+    "and begin with a lower case letter.\n",
+    "a1 could be a variable name.\n",
+    "'''\n",
+    "sents = nltk.sent_tokenize(text)\n",
+    "print(len(sents))\n",
+    "print()\n",
+    "for s in sents:\n",
+    "    print(s)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.10.8"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}