diff --git a/blake2b/blake2x.go b/blake2b/blake2x.go
index c814496a76..52c414db0e 100644
--- a/blake2b/blake2x.go
+++ b/blake2b/blake2x.go
@@ -29,7 +29,7 @@ type XOF interface {
 }
 
 // OutputLengthUnknown can be used as the size argument to NewXOF to indicate
-// the the length of the output is not known in advance.
+// the length of the output is not known in advance.
 const OutputLengthUnknown = 0
 
 // magicUnknownOutputLength is a magic value for the output size that indicates
diff --git a/blake2s/blake2x.go b/blake2s/blake2x.go
index eaff2a7f8d..828749ff01 100644
--- a/blake2s/blake2x.go
+++ b/blake2s/blake2x.go
@@ -29,7 +29,7 @@ type XOF interface {
 }
 
 // OutputLengthUnknown can be used as the size argument to NewXOF to indicate
-// the the length of the output is not known in advance.
+// the length of the output is not known in advance.
 const OutputLengthUnknown = 0
 
 // magicUnknownOutputLength is a magic value for the output size that indicates
diff --git a/cryptobyte/builder.go b/cryptobyte/builder.go
index 29b4c76412..765bf8e0a8 100644
--- a/cryptobyte/builder.go
+++ b/cryptobyte/builder.go
@@ -51,7 +51,7 @@ func NewFixedBuilder(buffer []byte) *Builder {
 }
 
 // Bytes returns the bytes written by the builder or an error if one has
-// occurred during during building.
+// occurred during building.
 func (b *Builder) Bytes() ([]byte, error) {
 	if b.err != nil {
 		return nil, b.err
diff --git a/ocsp/ocsp.go b/ocsp/ocsp.go
index 5edc9c97c2..f079d9eab6 100644
--- a/ocsp/ocsp.go
+++ b/ocsp/ocsp.go
@@ -63,7 +63,7 @@ func (r ResponseStatus) String() string {
 }
 
 // ResponseError is an error that may be returned by ParseResponse to indicate
-// that the response itself is an error, not just that its indicating that a
+// that the response itself is an error, not just that it's indicating that a
 // certificate is revoked, unknown, etc.
 type ResponseError struct {
 	Status ResponseStatus
diff --git a/openpgp/packet/userattribute.go b/openpgp/packet/userattribute.go
index 96a2b382a1..d19ffbc786 100644
--- a/openpgp/packet/userattribute.go
+++ b/openpgp/packet/userattribute.go
@@ -80,7 +80,7 @@ func (uat *UserAttribute) Serialize(w io.Writer) (err error) {
 
 // ImageData returns zero or more byte slices, each containing
 // JPEG File Interchange Format (JFIF), for each photo in the
-// the user attribute packet.
+// user attribute packet.
 func (uat *UserAttribute) ImageData() (imageData [][]byte) {
 	for _, sp := range uat.Contents {
 		if sp.SubType == UserAttrImageSubpacket && len(sp.Contents) > 16 {
diff --git a/ripemd160/ripemd160.go b/ripemd160/ripemd160.go
index 6c6e84236a..fd97ba1b06 100644
--- a/ripemd160/ripemd160.go
+++ b/ripemd160/ripemd160.go
@@ -5,7 +5,7 @@
 // Package ripemd160 implements the RIPEMD-160 hash algorithm.
 package ripemd160 // import "golang.org/x/crypto/ripemd160"
 
-// RIPEMD-160 is designed by by Hans Dobbertin, Antoon Bosselaers, and Bart
+// RIPEMD-160 is designed by Hans Dobbertin, Antoon Bosselaers, and Bart
 // Preneel with specifications available at:
 // http://homes.esat.kuleuven.be/~cosicart/pdf/AB-9601/AB-9601.pdf.
 
diff --git a/scrypt/scrypt.go b/scrypt/scrypt.go
index 9b25b5ac25..3362afd118 100644
--- a/scrypt/scrypt.go
+++ b/scrypt/scrypt.go
@@ -29,7 +29,7 @@ func blockXOR(dst, src []uint32, n int) {
 }
 
 // salsaXOR applies Salsa20/8 to the XOR of 16 numbers from tmp and in,
-// and puts the result into both both tmp and out.
+// and puts the result into both tmp and out.
 func salsaXOR(tmp *[16]uint32, in, out []uint32) {
 	w0 := tmp[0] ^ in[0]
 	w1 := tmp[1] ^ in[1]
diff --git a/sha3/doc.go b/sha3/doc.go
index a0ee3ae725..c2fef30aff 100644
--- a/sha3/doc.go
+++ b/sha3/doc.go
@@ -43,7 +43,7 @@
 // is then "full" and the permutation is applied to "empty" it. This process is
 // repeated until all the input has been "absorbed". The input is then padded.
 // The digest is "squeezed" from the sponge in the same way, except that output
-// output is copied out instead of input being XORed in.
+// is copied out instead of input being XORed in.
 //
 // A sponge is parameterized by its generic security strength, which is equal
 // to half its capacity; capacity + rate is equal to the permutation's width.
diff --git a/ssh/client.go b/ssh/client.go
index ae6ca775ee..7b00bff1ca 100644
--- a/ssh/client.go
+++ b/ssh/client.go
@@ -185,7 +185,7 @@ func Dial(network, addr string, config *ClientConfig) (*Client, error) {
 // keys.  A HostKeyCallback must return nil if the host key is OK, or
 // an error to reject it. It receives the hostname as passed to Dial
 // or NewClientConn. The remote address is the RemoteAddr of the
-// net.Conn underlying the the SSH connection.
+// net.Conn underlying the SSH connection.
 type HostKeyCallback func(hostname string, remote net.Addr, key PublicKey) error
 
 // BannerCallback is the function type used for treat the banner sent by
diff --git a/ssh/mux_test.go b/ssh/mux_test.go
index d88b64e43b..94596ec2d7 100644
--- a/ssh/mux_test.go
+++ b/ssh/mux_test.go
@@ -20,7 +20,7 @@ func muxPair() (*mux, *mux) {
 	return s, c
 }
 
-// Returns both ends of a channel, and the mux for the the 2nd
+// Returns both ends of a channel, and the mux for the 2nd
 // channel.
 func channelPair(t *testing.T) (*channel, *channel, *mux) {
 	c, s := muxPair()