The following pages help you to learn how to refer to past, present and future in English.

Test your Tenses

Monash University’s tense review gives you the chance to check whether you use tenses correctly. http://www.monash.edu.au/lls/llonline/grammar/tense/5.xml

All Tenses

Choose a tense and read the explanation of how it is used, then practise with their exercises. This page also allows you to compare uses of tenses and offers further links.http://www.englishpage.com/verbpage/simplepresent.html

Kenneth Beare’s ESL explains how individual tenses are formed and used, compares different tenses and gives you some quizzes to practice. 
http://esl.about.com/od/englishgrammar/a/tense_resource.htm

This page explains which verbs (to see, to love etc.) are not often used in the progressive or continuous form.
http://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv319.shtml

This Directory of Tenses give you a short introduction to their use and some examples. The design of the page is not particularly clear, but it offers short explanations that help to compare the use of different tenses. 
http://grammar.ccc.commnet.edu/grammar/tenses/tense_frames.htm

The following page does not explain HOW tenses are used, but offers a helpful training tool for irregular verbs:

http://www.verbs-online.com/

'I study at GCU' - 'I am studying in the library at the moment' - Present Simple and Present Continuous

Monash University offers an online tutorial about the difference between present simple and present continuous, explaining how they are formed and how they are used with the help of texts. After each step exercises allow you to check whether you understood their explanation.
http://www.monash.edu.au/lls/llonline/grammar/tense/1.xml

Talking about the Past

More Monash Tutorials about the present perfect (compared to the simple past) http://www.monash.edu.au/lls/llonline/grammar/tense/2.xml 
and about the past perfect 
http://www.monash.edu.au/lls/llonline/grammar/tense/3.xml

This page explains how to refer to the future in the past, for example, when you explain the plans you made yesterday for today.
http://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv213.shtml

Talking about the Future

An explanation of the future tenses from the BBC Ask about English webpage, also available as an audiofile.
http://www.bbc.co.uk/worldservice/learningenglish/radio/specials/1837_aae/page13.shtml

The differences between ‘I’m going to’, ‘I will be going to’ and ‘I’m doing’ explained: http://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv332.shtml

This quiz tests whether you use the correct tenses when talking about the future. http://www.usingenglish.com/handouts/146.html