"Anna(r) and the King" - R liaison in English

In non-rhotic varieties of English, such as Southern Standard British English (also known as RP), a small non-phonetic glide is commonly thought to separate two vowels across a word boundary. The two glides that are thought to be used are mini articulations of [j] and [w] (the sounds at the beginning of the words yoyo and window). Alternatively, such speakers may use an /r/ to separate the vowel at the end of a word from another following vowel. Here are some examples:

  • The end /ðijend/ "Thee yend"
  • Two uzies /tu:wu:zi:z/ "Two wuzies"
  • Law and order /lɔ:r ən ɔ:də/ "Lawran order"

Which sounds are used where:

You might notice that a [j] sound (the Y in yoyo), is very like the vowel [i] in bee /bi:/, and also similar to the vowel [ɪ] in kit /kɪt/. These three sounds may all be phonetically characterised as high front vowel sounds. If the vowel at the end of the first word ends as a high front vowel (if it ends with an /i:/ or a dipthong ending in /ɪ/) then a [j]-glide may be percieved between the two words. This is what we see in the string:

  • /ðijend/ "thee yend"

You might also notice that [w] is very similar to the [u] and [ʊ] vowels. These are all phonetically high back vowels. If the vowel at the end of the first word has a high back quality, then a [w]-glide may be perceived between the two vowels. This is what we see in the string:

  • /tu:wu:zi:z/ "Two wuzies"

In all other cases—where the vowel is therefore a non-high vowel—an /r/ may be used to separate the two syllables. This is what we see in the string:

  • Law and order /lɔ:r ən ɔ:də/ "Lawran order"

The first word law ends in a non-high back vowel, /ɔ:/, and it is this which provides the right conditions for the use of an intrusive /r/.

The Original Poster's question:

In the string Anna and the first word ends with a schwa vowel, /ə/. This is a mid, central vowel, and is therefore not a high vowel. This rules out a [j] or [w] glide and at the same time allows for an intrusive /r/. Notice that this intrusive /r/ is not mandatory, and at one time was sneered at by prescriptivists—although those days have now passed.