diff --git a/spacy/lang/en/stop_words.py b/spacy/lang/en/stop_words.py
index 4301e7d86..aae3e5e01 100644
--- a/spacy/lang/en/stop_words.py
+++ b/spacy/lang/en/stop_words.py
@@ -39,7 +39,7 @@ made make many may me meanwhile might mine more moreover most mostly move much
 must my myself
 
 name namely neither never nevertheless next nine no nobody none noone nor not
-nothing now nowhere n't
+nothing now nowhere 
 
 of off often on once one only onto or other others otherwise our ours ourselves
 out over own
@@ -66,7 +66,13 @@ whereafter whereas whereby wherein whereupon wherever whether which while
 whither who whoever whole whom whose why will with within without would
 
 yet you your yours yourself yourselves
-
-'d 'll 'm 're 's 've
 """.split()
 )
+
+contractions = ["n't", "'d", "'ll", "'m", "'re", "'s", "'ve"]
+STOP_WORDS.update(contractions)
+
+for apostrophe in ["‘", "’"]:
+    for stopword in contractions:
+        STOP_WORDS.add(stopword.replace("'", apostrophe))
+
diff --git a/spacy/tests/regression/test_issue3449.py b/spacy/tests/regression/test_issue3449.py
new file mode 100644
index 000000000..61a76334a
--- /dev/null
+++ b/spacy/tests/regression/test_issue3449.py
@@ -0,0 +1,25 @@
+# coding: utf8
+from __future__ import unicode_literals
+
+import pytest
+
+from spacy.lang.en import English
+
+
+@pytest.mark.xfail(reason="Current default suffix rules avoid one upper-case letter before a dot.")
+def test_issue3449():
+    nlp = English()
+    nlp.add_pipe(nlp.create_pipe('sentencizer'))
+
+    text1 = "He gave the ball to I. Do you want to go to the movies with I?"
+    text2 = "He gave the ball to I.  Do you want to go to the movies with I?"
+    text3 = "He gave the ball to I.\nDo you want to go to the movies with I?"
+
+    t1 = nlp(text1)
+    t2 = nlp(text2)
+    t3 = nlp(text3)
+
+    assert t1[5].text == 'I'
+    assert t2[5].text == 'I'
+    assert t3[5].text == 'I'
+
diff --git a/spacy/tests/regression/test_issue3521.py b/spacy/tests/regression/test_issue3521.py
new file mode 100644
index 000000000..6d841894a
--- /dev/null
+++ b/spacy/tests/regression/test_issue3521.py
@@ -0,0 +1,19 @@
+# coding: utf8
+from __future__ import unicode_literals
+
+import pytest
+
+
+@pytest.mark.parametrize(
+    "word",
+    [
+        "don't",
+        "don’t",
+        "I'd",
+        "I’d",
+    ],
+)
+def test_issue3521(en_tokenizer, word):
+    tok = en_tokenizer(word)[1]
+    # 'not' and 'would' should be stopwords, also in their abbreviated forms
+    assert tok.is_stop