diff --git a/doc/man3/CMS_get0_SignerInfos.pod b/doc/man3/CMS_get0_SignerInfos.pod
index 7abe39f411ce6f8613a67d8c59575ac323c36317..18237dcfce31eb6502752b021bb98356c970ebfd 100644
--- a/doc/man3/CMS_get0_SignerInfos.pod
+++ b/doc/man3/CMS_get0_SignerInfos.pod
@@ -55,7 +55,7 @@ CMS_SignerInfo_set1_signer_cert().
 
 Once all signer certificates have been set CMS_verify() can be used.
 
-Although CMS_get0_SignerInfos() can return NULL is an error occur B<or> if
+Although CMS_get0_SignerInfos() can return NULL if an error occurs B<or> if
 there are no signers this is not a problem in practice because the only
 error which can occur is if the B<cms> structure is not of type signedData
 due to application error.
diff --git a/doc/man3/CMS_get1_ReceiptRequest.pod b/doc/man3/CMS_get1_ReceiptRequest.pod
index 4f7f245193fa53ad8d30d16ea454632d209a353f..ba70480050de6fa119094ad9327dc9c4acc7c71d 100644
--- a/doc/man3/CMS_get1_ReceiptRequest.pod
+++ b/doc/man3/CMS_get1_ReceiptRequest.pod
@@ -54,7 +54,7 @@ CMS_verify().
 CMS_ReceiptRequest_create0() returns a signed receipt request structure or
 NULL if an error occurred.
 
-CMS_add1_ReceiptRequest() returns 1 for success or 0 is an error occurred.
+CMS_add1_ReceiptRequest() returns 1 for success or 0 if an error occurred.
 
 CMS_get1_ReceiptRequest() returns 1 is a signed receipt request is found and
 decoded. It returns 0 if a signed receipt request is not present and -1 if
diff --git a/doc/man3/OBJ_nid2obj.pod b/doc/man3/OBJ_nid2obj.pod
index 6c1aa1321f47c3c55a01c5a53c52335dbacb00d1..6d85c1111c5bd323cf8141686d2da73c8fe5daf5 100644
--- a/doc/man3/OBJ_nid2obj.pod
+++ b/doc/man3/OBJ_nid2obj.pod
@@ -54,7 +54,7 @@ constants.
 
 OBJ_nid2obj(), OBJ_nid2ln() and OBJ_nid2sn() convert the NID B<n> to
 an ASN1_OBJECT structure, its long name and its short name respectively,
-or B<NULL> is an error occurred.
+or B<NULL> if an error occurred.
 
 OBJ_obj2nid(), OBJ_ln2nid(), OBJ_sn2nid() return the corresponding NID
 for the object B<o>, the long name <ln> or the short name <sn> respectively
diff --git a/doc/man3/SMIME_read_PKCS7.pod b/doc/man3/SMIME_read_PKCS7.pod
index 3eb8bbc9a0f81268ef9f53259b013afe7b130df1..40973d3f4473676f4dac7c494d9602a91591defd 100644
--- a/doc/man3/SMIME_read_PKCS7.pod
+++ b/doc/man3/SMIME_read_PKCS7.pod
@@ -57,7 +57,7 @@ streaming single pass option should be available.
 =head1 RETURN VALUES
 
 SMIME_read_PKCS7() returns a valid B<PKCS7> structure or B<NULL>
-is an error occurred. The error can be obtained from ERR_get_error(3).
+if an error occurred. The error can be obtained from ERR_get_error(3).
 
 =head1 SEE ALSO