Update draft-ietf-quic-recovery.md

Co-authored-by: Martin Thomson <mt@lowentropy.net>

draft-ietf-quic-recovery.md

@@ -828,7 +828,7 @@ packets.
 When an ACK frame is received that establishes loss of all in-flight packets
 sent over a long enough period of time across all the packet number spaces, the
 network is considered to be experiencing persistent congestion.  The
-rationale for this threshold is to enable a sender to use initial PTOs for
+rationale for this threshold is to allow a sender to initially use PTOs for
 aggressive probing, as TCP does with Tail Loss Probe (TLP; see {{RACK}}), before
 establishing persistent congestion, as TCP does with a Retransmission Timeout
 (RTO; see {{?RFC5681}}). The RECOMMENDED value for