diff --git a/libsndio/sndio.7 b/libsndio/sndio.7
index 3447c1b..fef53e7 100644
--- a/libsndio/sndio.7
+++ b/libsndio/sndio.7
@@ -40,11 +40,11 @@ To overcome hardware limitations and to allow multiple applications
 to share the hardware,
 .Xr sndiod 1
 can be used.
-It exposes one or more software subdevices backed by the underlying hardware,
+It exposes one or more software sub-devices backed by the underlying hardware,
 while doing all necessary conversions on the fly.
 It can mix multiple streams or split the hardware into
-multiple subdevices, to allow programs to use the hardware
-concurently.
+multiple sub-devices, to allow programs to use the hardware
+concurrently.
 .Pp
 Hardware MIDI ports correspond to serial connectors provided by the
 .Xr midi 4