diff --git a/can-calc-bit-timing.c b/can-calc-bit-timing.c
index a9fb992..ecf5cb6 100644
--- a/can-calc-bit-timing.c
+++ b/can-calc-bit-timing.c
@@ -26,7 +26,7 @@
 #define ENOTSUPP	524	/* Operation is not supported */
 #endif
 
-/* usefull defines */
+/* useful defines */
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
 
 #define do_div(a,b) a = (a) / (b)
diff --git a/candump.c b/candump.c
index b489cd9..c865bd7 100644
--- a/candump.c
+++ b/candump.c
@@ -701,7 +701,7 @@ int main(int argc, char **argv)
 					/* log CAN frame with absolute timestamp & device */
 					fprintf(logfile, "(%010ld.%06ld) ", tv.tv_sec, tv.tv_usec);
 					fprintf(logfile, "%*s ", max_devname_len, devname[idx]);
-					/* without seperator as logfile use-case is parsing */
+					/* without separator as logfile use-case is parsing */
 					fprint_canframe(logfile, &frame, "\n", 0, maxdlen);
 				}
 
diff --git a/canlogserver.c b/canlogserver.c
index 6ad2078..e3350b7 100644
--- a/canlogserver.c
+++ b/canlogserver.c
@@ -97,7 +97,7 @@ void print_usage(char *prg)
 	fprintf(stderr, "       <received_can_id> & mask == value & mask\n");
 	fprintf(stderr, "\n");
 	fprintf(stderr, "When using more than one CAN interface the options\n");
-	fprintf(stderr, "m/v/i/e have comma seperated values e.g. '-m 0,7FF,0'\n");
+	fprintf(stderr, "m/v/i/e have comma separated values e.g. '-m 0,7FF,0'\n");
 	fprintf(stderr, "\nUse interface name '%s' to receive from all CAN interfaces.\n\n", ANYDEV);
 }
 
diff --git a/cansend.c b/cansend.c
index f12e924..aec64a5 100644
--- a/cansend.c
+++ b/cansend.c
@@ -79,7 +79,7 @@ int main(int argc, char **argv)
 		fprintf(stderr, "    <can_id>##<flags>{data}    for CAN FD frames\n\n");
 		fprintf(stderr, "<can_id> can have 3 (SFF) or 8 (EFF) hex chars\n");
 		fprintf(stderr, "{data} has 0..8 (0..64 CAN FD) ASCII hex-values (optionally");
-		fprintf(stderr, " seperated by '.')\n");
+		fprintf(stderr, " separated by '.')\n");
 		fprintf(stderr, "<flags> a single ASCII Hex value (0 .. F) which defines");
 		fprintf(stderr, " canfd_frame.flags\n\n");
 		fprintf(stderr, "e.g. 5A1#11.2233.44556677.88 / 123#DEADBEEF / 5AA# / ");
diff --git a/lib.c b/lib.c
index 9fb1056..2755c80 100644
--- a/lib.c
+++ b/lib.c
@@ -192,7 +192,7 @@ int parse_canframe(char *cs, struct canfd_frame *cf) {
 
 	for (i=0, dlen=0; i < maxdlen; i++){
 
-		if(cs[idx] == DATA_SEPERATOR) /* skip (optional) seperator */
+		if(cs[idx] == DATA_SEPERATOR) /* skip (optional) separator */
 			idx++;
 
 		if(idx >= len) /* end of string => end of data */
diff --git a/lib.h b/lib.h
index 805914c..4f73743 100644
--- a/lib.h
+++ b/lib.h
@@ -102,7 +102,7 @@ int parse_canframe(char *cs, struct canfd_frame *cf);
  * CAN FD frames
  * - string layout <can_id>##<flags>{data}
  * - <flags> a single ASCII Hex value (0 .. F) which defines canfd_frame.flags
- * - {data} has 0 to 64 hex-values that can (optionally) be seperated by '.'
+ * - {data} has 0 to 64 hex-values that can (optionally) be separated by '.'
  * - return value on successful parsing: CANFD_MTU
  *
  * Return value on detected problems: 0
@@ -146,7 +146,7 @@ void fprint_canframe(FILE *stream , struct canfd_frame *cf, char *eol, int sep,
 void sprint_canframe(char *buf , struct canfd_frame *cf, int sep, int maxdlen);
 /*
  * Creates a CAN frame hexadecimal output in compact format.
- * The CAN data[] is seperated by '.' when sep != 0.
+ * The CAN data[] is separated by '.' when sep != 0.
  *
  * The type of the CAN frame (CAN 2.0 / CAN FD) is specified by maxdlen:
  * maxdlen = 8 -> CAN2.0 frame