diff --git a/feat-core/EnumSig.ml b/feat-core/EnumSig.ml
index da07fc33b9a1dd2bf0a9324ffd2cf9526b4b7ee4..b487548d1364a180f2e97b6ad0c4ff8fecbb4932 100644
--- a/feat-core/EnumSig.ml
+++ b/feat-core/EnumSig.ml
@@ -122,9 +122,9 @@ module type ENUM = sig
   (**[sample m e i j k] is a sequence of at most [m] elements of every size
      comprised between [i] (included) and [j] (excluded) extracted out of the
      enumeration [e], prepended in front of the existing sequence [k]. At
-     every size, if there at most [m] elements of this size, then all elements
-     of this size are produced; otherwise, a random sample of [m] elements of
-     this size is produced. *)
+     every size, if there are at most [m] elements of this size, then all
+     elements of this size are produced; otherwise, a random sample of [m]
+     elements of this size is produced. *)
   val sample: int -> 'a enum -> int -> int -> 'a Seq.t -> 'a Seq.t
 
 end
diff --git a/feat-core/IFSeqSig.ml b/feat-core/IFSeqSig.ml
index 343f692b297904e983cc2d77c88c4d587ef9c281..ee2b4b2e6d4237fe496bce4fbf646c0401fc73be 100644
--- a/feat-core/IFSeqSig.ml
+++ b/feat-core/IFSeqSig.ml
@@ -102,7 +102,7 @@ module type IFSEQ_EXTENDED = sig
 
   (**[sample m s k] is an explicit sequence of at most [m] elements extracted
      out of the implicit sequence [s], prepended in front of the existing
-     sequence [k]. If [length s] at most [m], then all elements of [s] are
+     sequence [k]. If [length s] is at most [m], then all elements of [s] are
      produced. Otherwise, a random sample of [m] elements extracted out of [s]
      is produced. *)
   val sample: int -> 'a seq -> 'a Seq.t -> 'a Seq.t