diff --git a/contrib/seeds/generate-seeds.py b/contrib/seeds/generate-seeds.py
--- a/contrib/seeds/generate-seeds.py
+++ b/contrib/seeds/generate-seeds.py
@@ -131,7 +131,7 @@
     g.write(' *\n')
     g.write(' * Each line contains a 16-byte IPv6 address and a port.\n')
     g.write(
-        ' * IPv4 as well as onion addresses are wrapped inside a IPv6 address accordingly.\n')
+        ' * IPv4 as well as onion addresses are wrapped inside an IPv6 address accordingly.\n')
     g.write(' */\n')
     with open(os.path.join(indir, 'nodes_main.txt'), 'r') as f:
         process_nodes(g, f, 'pnSeed6_main', 8333)
diff --git a/src/chainparamsseeds.h b/src/chainparamsseeds.h
--- a/src/chainparamsseeds.h
+++ b/src/chainparamsseeds.h
@@ -5,7 +5,7 @@
  * @generated by contrib/seeds/generate-seeds.py
  *
  * Each line contains a 16-byte IPv6 address and a port.
- * IPv4 as well as onion addresses are wrapped inside a IPv6 address accordingly.
+ * IPv4 as well as onion addresses are wrapped inside an IPv6 address accordingly.
  */
 static SeedSpec6 pnSeed6_main[] = {
     {{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xff,0xff,0x03,0x55,0x70,0x3e}, 8333},
diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -113,7 +113,7 @@
 }
 
 std::string DummyAddress(const Config &config) {
-    // Just some dummy data to generate an convincing random-looking (but
+    // Just some dummy data to generate a convincing random-looking (but
     // consistent) address
     static const std::vector<uint8_t> dummydata = {
         0xeb, 0x15, 0x23, 0x1d, 0xfc, 0xeb, 0x60, 0x92, 0x58, 0x86,
diff --git a/src/script/ismine.h b/src/script/ismine.h
--- a/src/script/ismine.h
+++ b/src/script/ismine.h
@@ -32,7 +32,7 @@
 
 /**
  * isInvalid becomes true when the script is found invalid by consensus or
- * policy. This will terminate the recursion and return a ISMINE_NO immediately,
+ * policy. This will terminate the recursion and return ISMINE_NO immediately,
  * as an invalid script should never be considered as "mine". Currently the only
  * use of isInvalid is indicate uncompressed keys when
  * SCRIPT_VERIFY_COMPRESSED_PUBKEYTYPE is specified, but could also be used in
diff --git a/src/test/data/tx_invalid.json b/src/test/data/tx_invalid.json
--- a/src/test/data/tx_invalid.json
+++ b/src/test/data/tx_invalid.json
@@ -92,11 +92,11 @@
 [[["60a20bd93aa49ab4b28d514ec10b06e1829ce6818ec06cd3aabd013ebcdc4bb1", 0, "1 0x41 0x04cc71eb30d653c0c3163990c47b976f3fb3f37cccdcbedb169a1dfef58bbfbfaff7d8a473e7e2e6d317b87bafe8bde97e3cf8f065dec022b51d11fcdd0d348ac4 0x41 0x0461cbdcc5409fb4b4d42b51d33381354d80e550078cb532a34bfa2fcfdeb7d76519aecc62770f5b0e4ef8551946d8a540911abe3e7854a26f39f58b25c15342af 2 OP_CHECKMULTISIG"]],
 "0100000001b14bdcbc3e01bdaad36cc08e81e69c82e1060bc14e518db2b49aa43ad90ba260000000004a010047304402203f16c6f40162ab686621ef3000b04e75418a0c0cb2d8aebeac894ae360ac1e780220ddc15ecdfc3507ac48e1681a33eb60996631bf6bf5bc0a0682c4db743ce7ca2b01ffffffff0140420f00000000001976a914660d4ef3a743e3e696ad990364e555c271ad504b88ac00000000", "P2SH,NULLDUMMY"],
 
-["As above, but using a OP_1"],
+["As above, but using an OP_1"],
 [[["60a20bd93aa49ab4b28d514ec10b06e1829ce6818ec06cd3aabd013ebcdc4bb1", 0, "1 0x41 0x04cc71eb30d653c0c3163990c47b976f3fb3f37cccdcbedb169a1dfef58bbfbfaff7d8a473e7e2e6d317b87bafe8bde97e3cf8f065dec022b51d11fcdd0d348ac4 0x41 0x0461cbdcc5409fb4b4d42b51d33381354d80e550078cb532a34bfa2fcfdeb7d76519aecc62770f5b0e4ef8551946d8a540911abe3e7854a26f39f58b25c15342af 2 OP_CHECKMULTISIG"]],
 "0100000001b14bdcbc3e01bdaad36cc08e81e69c82e1060bc14e518db2b49aa43ad90ba26000000000495147304402203f16c6f40162ab686621ef3000b04e75418a0c0cb2d8aebeac894ae360ac1e780220ddc15ecdfc3507ac48e1681a33eb60996631bf6bf5bc0a0682c4db743ce7ca2b01ffffffff0140420f00000000001976a914660d4ef3a743e3e696ad990364e555c271ad504b88ac00000000", "P2SH,NULLDUMMY"],
 
-["As above, but using a OP_1NEGATE"],
+["As above, but using an OP_1NEGATE"],
 [[["60a20bd93aa49ab4b28d514ec10b06e1829ce6818ec06cd3aabd013ebcdc4bb1", 0, "1 0x41 0x04cc71eb30d653c0c3163990c47b976f3fb3f37cccdcbedb169a1dfef58bbfbfaff7d8a473e7e2e6d317b87bafe8bde97e3cf8f065dec022b51d11fcdd0d348ac4 0x41 0x0461cbdcc5409fb4b4d42b51d33381354d80e550078cb532a34bfa2fcfdeb7d76519aecc62770f5b0e4ef8551946d8a540911abe3e7854a26f39f58b25c15342af 2 OP_CHECKMULTISIG"]],
 "0100000001b14bdcbc3e01bdaad36cc08e81e69c82e1060bc14e518db2b49aa43ad90ba26000000000494f47304402203f16c6f40162ab686621ef3000b04e75418a0c0cb2d8aebeac894ae360ac1e780220ddc15ecdfc3507ac48e1681a33eb60996631bf6bf5bc0a0682c4db743ce7ca2b01ffffffff0140420f00000000001976a914660d4ef3a743e3e696ad990364e555c271ad504b88ac00000000", "P2SH,NULLDUMMY"],
 
diff --git a/src/test/data/tx_valid.json b/src/test/data/tx_valid.json
--- a/src/test/data/tx_valid.json
+++ b/src/test/data/tx_valid.json
@@ -23,11 +23,11 @@
 [[["60a20bd93aa49ab4b28d514ec10b06e1829ce6818ec06cd3aabd013ebcdc4bb1", 0, "1 0x41 0x04cc71eb30d653c0c3163990c47b976f3fb3f37cccdcbedb169a1dfef58bbfbfaff7d8a473e7e2e6d317b87bafe8bde97e3cf8f065dec022b51d11fcdd0d348ac4 0x41 0x0461cbdcc5409fb4b4d42b51d33381354d80e550078cb532a34bfa2fcfdeb7d76519aecc62770f5b0e4ef8551946d8a540911abe3e7854a26f39f58b25c15342af 2 OP_CHECKMULTISIG"]],
 "0100000001b14bdcbc3e01bdaad36cc08e81e69c82e1060bc14e518db2b49aa43ad90ba260000000004a01ff47304402203f16c6f40162ab686621ef3000b04e75418a0c0cb2d8aebeac894ae360ac1e780220ddc15ecdfc3507ac48e1681a33eb60996631bf6bf5bc0a0682c4db743ce7ca2b01ffffffff0140420f00000000001976a914660d4ef3a743e3e696ad990364e555c271ad504b88ac00000000", "P2SH"],
 
-["As above, but using a OP_1"],
+["As above, but using an OP_1"],
 [[["60a20bd93aa49ab4b28d514ec10b06e1829ce6818ec06cd3aabd013ebcdc4bb1", 0, "1 0x41 0x04cc71eb30d653c0c3163990c47b976f3fb3f37cccdcbedb169a1dfef58bbfbfaff7d8a473e7e2e6d317b87bafe8bde97e3cf8f065dec022b51d11fcdd0d348ac4 0x41 0x0461cbdcc5409fb4b4d42b51d33381354d80e550078cb532a34bfa2fcfdeb7d76519aecc62770f5b0e4ef8551946d8a540911abe3e7854a26f39f58b25c15342af 2 OP_CHECKMULTISIG"]],
 "0100000001b14bdcbc3e01bdaad36cc08e81e69c82e1060bc14e518db2b49aa43ad90ba26000000000495147304402203f16c6f40162ab686621ef3000b04e75418a0c0cb2d8aebeac894ae360ac1e780220ddc15ecdfc3507ac48e1681a33eb60996631bf6bf5bc0a0682c4db743ce7ca2b01ffffffff0140420f00000000001976a914660d4ef3a743e3e696ad990364e555c271ad504b88ac00000000", "P2SH"],
 
-["As above, but using a OP_1NEGATE"],
+["As above, but using an OP_1NEGATE"],
 [[["60a20bd93aa49ab4b28d514ec10b06e1829ce6818ec06cd3aabd013ebcdc4bb1", 0, "1 0x41 0x04cc71eb30d653c0c3163990c47b976f3fb3f37cccdcbedb169a1dfef58bbfbfaff7d8a473e7e2e6d317b87bafe8bde97e3cf8f065dec022b51d11fcdd0d348ac4 0x41 0x0461cbdcc5409fb4b4d42b51d33381354d80e550078cb532a34bfa2fcfdeb7d76519aecc62770f5b0e4ef8551946d8a540911abe3e7854a26f39f58b25c15342af 2 OP_CHECKMULTISIG"]],
 "0100000001b14bdcbc3e01bdaad36cc08e81e69c82e1060bc14e518db2b49aa43ad90ba26000000000494f47304402203f16c6f40162ab686621ef3000b04e75418a0c0cb2d8aebeac894ae360ac1e780220ddc15ecdfc3507ac48e1681a33eb60996631bf6bf5bc0a0682c4db743ce7ca2b01ffffffff0140420f00000000001976a914660d4ef3a743e3e696ad990364e555c271ad504b88ac00000000", "P2SH"],
 
diff --git a/test/functional/p2p_fingerprint.py b/test/functional/p2p_fingerprint.py
--- a/test/functional/p2p_fingerprint.py
+++ b/test/functional/p2p_fingerprint.py
@@ -4,7 +4,7 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Test various fingerprinting protections.
 
-If an stale block more than a month old or its header are requested by a peer,
+If a stale block more than a month old or its header are requested by a peer,
 the node should pretend that it does not have it to avoid fingerprinting.
 """
 
diff --git a/test/functional/rpc_rawtransaction.py b/test/functional/rpc_rawtransaction.py
--- a/test/functional/rpc_rawtransaction.py
+++ b/test/functional/rpc_rawtransaction.py
@@ -284,7 +284,7 @@
         self.nodes[0].generate(1)
         self.sync_all()
 
-        # THIS IS A INCOMPLETE FEATURE
+        # THIS IS AN INCOMPLETE FEATURE
         # NODE2 HAS TWO OF THREE KEY AND THE FUNDS SHOULD BE SPENDABLE AND
         # COUNT AT BALANCE CALCULATION
         # for now, assume the funds of a 2of3 multisig tx are not marked as