diff --git a/spacy/en.pxd b/spacy/en.pxd
index 2ca081e47..66ccd64ce 100644
--- a/spacy/en.pxd
+++ b/spacy/en.pxd
@@ -131,4 +131,5 @@ cpdef enum:
 
 
 cdef class English(Language):
-    pass
+    cdef int is_base_np_end(self, const TokenC* token) except -1
+    cdef int is_outside_base_np(self, const TokenC* token) except -1
diff --git a/spacy/en.pyx b/spacy/en.pyx
index 80bea551f..ba4f747dd 100644
--- a/spacy/en.pyx
+++ b/spacy/en.pyx
@@ -205,6 +205,13 @@ cdef class English(Language):
             c += t[i].pos == golds[i]
         return c
 
+    cdef int is_base_np_end(self, const TokenC* token) except -1:
+        pass
+
+    cdef int is_outside_base_np(self, const TokenC* token) except -1:
+        pass
+
+
 
 cdef int fill_pos_context(atom_t* context, const int i, const TokenC* tokens) except -1:
     _fill_from_token(&context[P2_sic], &tokens[i-2])
diff --git a/spacy/lang.pxd b/spacy/lang.pxd
index 12714465c..de7ecd54a 100644
--- a/spacy/lang.pxd
+++ b/spacy/lang.pxd
@@ -54,6 +54,7 @@ cdef class Language:
     cpdef Tokens tokens_from_list(self, list strings)
     cpdef Tokens tokenize(self, unicode text)
 
+
     cdef int _try_cache(self, int idx, hash_t key, Tokens tokens) except -1
     cdef int _tokenize(self, Tokens tokens, UniStr* span, int start, int end) except -1
     cdef UniStr* _split_affixes(self, UniStr* string, vector[Lexeme*] *prefixes,
@@ -64,4 +65,7 @@ cdef class Language:
     cdef int _find_suffix(self, Py_UNICODE* characters, size_t length) except -1
     cdef int _find_infix(self, Py_UNICODE* characters, size_t length) except -1
     cdef int _save_cached(self, const TokenC* tokens, hash_t key, int n) except -1
+
+    cdef int is_base_np_end(self, const TokenC* token) except -1
+    cdef int is_outside_base_np(self, const TokenC* token) except -1
  
diff --git a/spacy/lang.pyx b/spacy/lang.pyx
index 4fc15e89b..f8fe7a0a3 100644
--- a/spacy/lang.pyx
+++ b/spacy/lang.pyx
@@ -81,6 +81,11 @@ cdef class Language:
         * The data/<lang>/prefix file, used to build a regex to split off prefixes;
         * The data/<lang>/suffix file, used to build a regex to split off suffixes.
 
+        The string is first split on whitespace.  To tokenize a whitespace-delimited
+        chunk, we first try to look it up in the special-cases. If it's not found,
+        we split off a prefix, and then try again. If it's still not found, we
+        split off a suffix, and repeat.
+
         Args:
             string (unicode): The string to be tokenized. 
 
@@ -274,6 +279,14 @@ cdef class Language:
             self._specials.set(string.key, cached)
             self._cache.set(string.key, cached)
 
+    cdef int is_base_np_end(self, const TokenC* token) except -1:
+        raise NotImplementedError
+
+    cdef int is_outside_base_np(self, const TokenC* token) except -1:
+        raise NotImplementedError
+        
+ 
+
 
 cdef int set_morph_from_dict(Morphology* morph, dict props) except -1:
     morph.number = props.get('number', 0)