in short

out of sight

at sea

in mind

on foot

To find the examples shown above:

1. Set the keyword string to 'ing' with the type field set to 'ends with'.
2. Set the 'Associated word' field to the verb you want ('avoid').
3. Select the 'Left of keyword only' radio button.
4. Select the corpus and press 'Go'.

The resulting concordances should be something like the following examples:

1    s he possibly  could to avoid brushing against the very, very dim  perimet
2     so that his heads could avoid looking at each  other,  because  neither  
3    is precisely what you will avoid doing because  the  average  Vogon  will 
4     been on it. I've tried to avoid being on it."    "You've still finished i
5     at us,   so if you could avoid laying your problems on us as well, I thin
6    easure not to be able to avoid meeting."    Zaphod took a  moment  or  two

How the concordancer can help

1. Question: I don't understand why "an" precedes "hereditary". Hereditary has a hard  /h/ sound, not like 'hour' or 'honor'. 

Answer: This can certainly be confusing. Often the 'H' as first letter may be sounded, but it is customary to write 'an' before the word, even though it may be sounded.

You can check this with the concordancer: 

• choose "associated word" 'AN' and search for words starting with 'H', 
• set the left of keyword flag with distance from keyword set to '4'. 

You will see something like the following:

 1    a debate on the introduction of an habitual residence test for   claiman
 2    e   cathedral which loomed like an hallucination in the gaps between bui
 3    rning the occupier of   part of an hereditament following the implementa
 4     deal with joint occupiers of an   hereditament or part thereof as conte
 5    dealt with joint   occupiers of an hereditament, not with the situation 
 8     for someone who   is after all an historian and supposed to have an ind
 9    of Peterhouse, Cambridge, and an   historian of the early Church.       
 10   d run by racing   in 1997 after an historic announcement in the Commons 
 11   able example of the survival of an historic culture   in the face of opp
 12   oaches cause too much damage to an historic park. The Northern Schools C
 13   .        Mr McFall said it was an "historic vote that signals the end of
 14   tary, that they are too much of an historical asset   to be starved of f

When 'an' precedes a noun starting with the letter 'H', even when the 'H' is not silent, there may be a tendency when speaking to make the 'H' weakly aspirated, as for example in "an hotel". However this is not a rule, and we could equally well say "a hotel" with a strongly aspirated 'H'.
In some dialects of English, such as London cockney, the 'H' is regularly made silent in speech, and the indefinite article 'an' is used, as for example "I know an 'otel where you can stay".

Here's an example from a report in The Times newspaper:

AN HEREDITARY peer failed in the Lords last night to gain support for a backbench Bill which would have ensured that his son, who was born out of wedlock, was able to inherit his title.

2. Question: When should I use 'as' after the word 'appoint'? Is it correct to say 'She was appointed the chairlady of the English Society.'? Or should I say 'She was appointed as the chairlady of the English Society.'?

Answer: Both of these examples are acceptable. A good way to look for examples of this sort of use is to use the concordancer with an associated word. If you search for appoint with the starts with flag set and associated word as (set right side only) you will see examples as follows:

6  bank, and the High Court, which appointed Ernst & Young as administrators a 
7 h those of the Methodist pulpit, appointed him as their first racing corresp 
8 dfruit Boulevard, Timothy Mo has appointed himself as his agent and public 
9 within the Thomson group. He was appointed instead as managing director of 
10 ment in the future. When he was appointed, Mr Chernomyrdin was seen as a br 
11  perfection of all presidential appointees will continue for as long as r 

3. Question: I wanted to ask what is the difference between spend on and spend in.

Answer:  Good question. Using the Web Concordancer to check how these differ gives the following examples from the Brown corpus: 

1  eck showing the amount the company spends on a particular fringe.  
2  t that if he was not "compelled to spend money on  useless lawyer's bills,  
3  elpful. Part of the time saved was spent on a preliminary estimate for a l
4   time and rags and polishes he had spent on keeping it up.  K28 0901  1      
5  a certain fury of the time she had spent on Latin verbs.    "Not since las
6  roads: 1) A great deal of time was spent on processes for solving marital  
7  ths! Most of our working days were spent on the telephone calling "bookies

1   midwestern vacation is a few days spent in cosmopolitan Chicago. Lake Mich
2  rial. Most of the impact energy is spent in crushing and fragmentation. Whe
3   the first day of deliberation was spent in going over the evidence.    She
4   As he informs Watson, "My life is spent in one long effort to escape from 
5  d guidance clinics where the hours spent in purely diagnostic study may equ
6   added to that which I had already spent in school prior to my induction in
7  nt at Sunnyvale. His spare time is spent in soaring gliders.    "It's so qu 

The above examples show that the verb spend is used mainly with reference to time and money. Referring to money, the preposition on indicates how or what the money was spent on.
Referring to time, the preposition in indicates how and doing what the time was spent, often used with a gerund following in.

• About the concordancer programs
• Using the concordancer to study prepositions