‘Behalf’ means ‘for someone’ else in the sense of representing the other person. It is only used with a few particular words:

on behalf of
in behalf of (American English)
on her/his/their behalf

The teacher spoke on behalf of the principal.
The principal could not be there, so the teacher spoke on her behalf.

When you learn new vocab, make sure that you note collocations too. For this group of words some collocations are:
on behalf of
bulk order, to bulk up, the bulk of
cessation of fighting, incessant noise
coherence of
coincide with

Check the meanings of the words if you don’t already know them. Check the meanings of the various forms as sometimes they are different. You can check them at Time4english by clicking the words (http://www.time4english.com/aamain/lounge/awl.asp).

Complete the sentences. Choose the correct word and then use the correct form of the word.

Vocabulary for IELTS – Academic Word List 98

1. Both teachers have the same family name, but it is just ______________; they are not related.  (coincident, cease)
2. She was very upset and as a result her story was somewhat. (coherent, coincide)
3. The holiday period _______________ when the cannon is fired. (behalf, cease)
4. The _______________ of the population are concerned about climate change, but still the politicians do nothing. (bulk, coherent)
5. On ______________ of the entire school, the principal thanked all of the volunteers. (bulk, behalf)

Answers (in the wrong order)
5. behalf   3. ceases   2. incoherent   1. coincidence     4. bulk