Tag Sequence Search is a way to retrieve grammatical patterns from a concordance. The basic idea is to fill in slots at different positions to the left and/or right of the search word or phrase using wordclass categories.

Tag Sequence Search comes in two modes: 'simple' and 'advanced'. In simple mode the slots are in fixed positions, but you can fill in as many slots as you like, up to a maximum of 8. In advanced mode you have more flexibility about the relative positions of the slots, and can choose to look for words as well as grammatical tags.

1. In the BNC Query Result window, select Tag sequence search from the drop-down menu and press 'Go!'
2. In BNC Tag Sequence Search Settings, you are asked whether tag sequences should be calculated 'over sentence boundaries'. Leave this as 'No' if you only want to retrieve sequences within the same sentence. Click 'Submit' and wait until the calculation has finished.

   

3. In the Tag Sequence Search menu, choose tag-restrictions for any positions within the window -4 to +4; that is, between four words to the left and four words to the right of the search word or phrase, called the 'node'.

   For example, suppose you have done a concordance for the word handsome. If you are interested in what kinds of nouns are modified by handsome, you could simply specify 'noun' in the position +1 (i.e. one to the right of the node). If you want to see a list of the matching nouns first, simply check the box for +1 under 'Compile frequency list for checked positions', then press 'Submit'. (See figure).



4. Selecting multiple positions. To look at handsome combining with other adjectives used to premodify nouns, you could select adjective at -2, conjunction at -1, and noun at +1. This will find examples like "large and handsome volumes", "amorous but handsome expression":

   

   For a different order of coordinated items, click 'Reset' and try conjunction at +1, adjective at +2, and noun at +3.

5. The part-of-speech tags listed below the categories noun, conj., adjective etc. allow you to be more specific about what to retrieve; e.g. the tag NN1 will find singular common nouns, AT0 will match articles (e.g. a, an, the, no), VBI the verb 'BE' in the infinitive form, and XX0 the negative particle (not and n't). So, if we add to the sequence for the figure above, putting VBI at position -4, and AT0 at -3, we get just two examples, "...would be a large and handsome structure..." and "...to be a tall and handsome woman..." (See full list of BNC grammatical tags.)

6. Selecting multiple items within one slot/position (e.g. all tags beginning VB-):
   • Continuous selection: click on the first item in the list (e.g. VBB), then hold the "Shift" key and click on the last item (e.g. VBZ)
   • Discontinuous selection:
     • Windows keyboard: hold the "Control" key and left-click on each individual item
     • Macintosh keyboard: hold the "Command" key and click on each individual item
     
     
7. Using 'any word'. To allow for sequences of tags that are not adjacent, you will need to select 'any word' in the position(s) between those positions that you have specified with an explicit tag:

   

8. Using 'boundary'. You can also set a sentence boundary as one of the positions. For example, to find handsome at the start of a sentence, set position -1 to 'boundary'.

The examples given in Simple search mode have found a range of patterns, but the fixed positions of the slots make it difficult to allow for much variation in the search. In advanced mode you can

• express optional slots in a tag sequence
• express that slots be excluded (i.e. not match)
• specify words, and not just tags, as necessary, excluded or optional
• reset the size of the 'window', i.e. the number of positions across which the specified sequence is to match
• fill up to two sequences of tags (i.e. two patterns) one sequence per row of boxes.

Advanced mode: steps

In Simple search mode, click on the button labeled 'Go to advanced mode' located in the bottom row of the table.

1. Setting optional values

Let's suppose you want to look at the nouns premodified by handsome, and want to allow for handsome coordinating with other adjectives before the noun, as well as direct premodification. You can find both types in one search as follows: set the first position (A) to conjunction and 'optional', the next position (B) to adjective and 'optional', and the next to noun and 'necessary'. Set the window size as +1 to +3 (see figure). This means that a noun must occur between 1 and 3 words to the right of handsome, but only a conjunction or adjective, or both, can intervene. (i.e. examples like "handsome man" and "handsome but cruel man" will be retrieved.)



NB. As with Simple Tag Sequences, if you don't fill a slot, no attempt is made to match it.

2. Adding a lexical restriction

   If you want to restrict the noun to only the word man, enter this word in the box below the tags. If you want to exclude man, put a '-' (minus sign) in front of the word:

               

3. Making a frequency list

You can make a list of all the words represented by a particular tag by checking the box below the drop-down menu.



4. Selecting multiple items in one position (e.g. all tags beginning VB-):
   • Continuous selection: click on the first item in the list (e.g. VBB), then hold the "Shift" key and click on the last item (e.g. VBZ)
   • Discontinuous selection:
     • Windows keyboard: hold the "Control" key and left-click on each individual item
     • Macintosh keyboard: hold the "Command" key and click on each individual item
     
     
5. Looking for the same tag(s) at different positions

Suppose you want to find all concordance lines where handsome is preceded within a space of 5 words by Existential there (which is tagged EX0 in the BNC). If you make the window size -1 to -5, BNCweb will try to find EX0 in every position available. (Cf. To do the same thing in Simple Mode, you would have to run five searches, in each one changing the position of EX0 and the number of optional 'Any word' slots that can intervene between EX0 and the node.)



You can use the same approach to look for more than one tag in a sequence, e.g. within the same 5-word window, EX0 followed by any word-form of the lemma BE (i.e. tags beginning VB-). BNCweb will try to find the sequence (EX0 immediately followed by VB-) at all possible positions (i.e. -5 and -4, -4 and -3, -3 and -2, and -2 and -1).

6. Adding another sequence of tags

You can combine two sequences of tags in one search, by using both of the rows of slots available. For example, you could restrict the last illustrated search in such a way that the only examples retrieved are those with a plural noun (tagged NN2) after handsome: e.g. "there are two handsome oast houses".

1. It is not possible to use one row to define a tag sequence which includes items on both sides of the node (e.g. from -2 to +2). You will have to use both rows for this kind of search.
2. There is a maximum of 2 optional positions for each row of slots.
3. It is not possible to set both "outer" positions (e.g. positions A and D) of a row as optional positions.
4. Only one of the two position rows can contain checked boxes for compiling a frequency list.