'Give up’? ‘Go on!’ – Phrasal Verbs

In combination with prepositions such as up,in, off etc. some English verbs acquire a different meaning that cannot be guessed from their basic form. A good example is to gowhich can be combined with a number of different prepositions. The meaning of these combinations, also called phrasal verbs, cannot be guessed simply from the meaning of ‘go’:
‘to go about something’ – to deal with something: “How can I go about solving this problem?”
‘to go at somebody’ – to attack somebody: “He went at him with a knife.”
‘to go down’ – to be remembered: "He went down in history as the first man to land on the moon."
‘to go off’ – to explode: “Suddenly a bomb went off.”

Phrasal verbs are very common in everyday spoken English, so if you want to get into them, check the weblinks below.

The Purdue Owl gives a good introduction to phrasal verbs and their use.
http://owl.english.purdue.edu/owl/resource/630/01/

A good list of common phrasal verbs can be found on
http://www2.gsu.edu/~wwwesl/egw/phraverb.htm

This page offers a slighly more unusual list. 
http://www.eslgold.com/idioms/phrasal.html

There's a useful and very user-friendly dictionary of phrasal verbs on

http://www.usingenglish.com/reference/phrasal-verbs/search.php?q=go

Alternatively you could use a Learner’s Dictionary and check verbs such as to have, to go, to get, to put, to come, to take... You might still want to practise, so have a look at these pages:

Match phrasal verbs and descriptions of their meaning. 
http://esl.about.com/library/vocabulary/blphrasalbuild1.htm
http://www.englishclub.com/esl-games/matching-phrasal-verbs-01.htm

Choose the appropriate phrasal verb for a sentence.
http://www.eflnet.com/pverbs/phrasal_verb_verb.php
http://www.learnenglishfeelgood.com/lefg_phrasalverbs1.pdf
http://www.linguarama.com/ps/297-5.htm

Important note: phrasal verbs are not generally used in academic writing: use 'go off' when speaking, but the more precise/formal verb 'explode' in academic writing.