2. Present Perfect vs Simple Past

3. Listen

4. Difference…

5. Form Simple PastPresent Perfect Simple irregular verbs: see 2nd column of irregular verbs Example:I spoke irregular verbs: form of 'have' + 3rd column of irregular verbs Example:I / you / we / they have spokenhe / she / it has spoken regular verbs: infinitive + ed Example:I worked Exceptions Exceptions when adding 'ed': when the final letter is e, only add dExample:love - loved after a short, stressed vowel, the final consonant is doubledExample:admit - admitted final l is always doubled in British English (not in American English)Example:travel - travelled after a consonant, final y becomes i (but: not after a vowel)Example:worry - worriedbut: play - played

6. Practice

7. Using the words in parentheses, complete the text below with the appropriate tenses Since computers were first introduced to the public in the early 1980's, technology (changed/ have changed) a great deal. The first computers (were, was) simple machines designed for basic tasks. They (did not have, did not has) much memory and they (were not, was not) very powerful.

8. Using the words in parentheses, complete the text below with the appropriate tenses Since computers were first introduced to the public in the early 1980's, technology technology has changed a great deal. The first computers (were, was) simple machines designed for basic tasks. They (did not have, did not has) much memory and they (were not, was not) very powerful.

9. Using the words in parentheses, complete the text below with the appropriate tenses Since computers were first introduced to the public in the early 1980's, technology technology has changed a great deal. The first computers were, simple machines designed for basic tasks. They (did not have, did not has) much memory and they (were not, was not) very powerful.

10. Using the words in parentheses, complete the text below with the appropriate tenses Since computers were first introduced to the public in the early 1980's, technology technology has changed a great deal. The first computers were, simple machines designed for basic tasks. They did not have, much memory and they (were not, was not) very powerful.

11. Using the words in parentheses, complete the text below with the appropriate tenses Since computers were first introduced to the public in the early 1980's, technology technology has changed a great deal. The first computers were, simple machines designed for basic tasks. They did not have, much memory and they were not very powerful.

12. Early computers were often quite expensive and customers often (payed, paid) thousands of dollars for machines which actually (do, did) very little. Most computers (were, was) separate, individual machines used mostly as expensive typewriters or for playing games.

13. Early computers were often quite expensive and customers often paid thousands of dollars for machines which actually (do, did) very little. Most computers (were, was) separate, individual machines used mostly as expensive typewriters or for playing games.

14. Early computers were often quite expensive and customers often paid thousands of dollars for machines which actually did very little. Most computers (were, was) separate, individual machines used mostly as expensive typewriters or for playing games.

15. Early computers were often quite expensive and customers often paid thousands of dollars for machines which actually did very little. Most computers were, separate, individual machines used mostly as expensive typewriters or for playing games.

16. Times (have change, has change). Computers (have become, has become) powerful machines with very practical applications. Programmers (has created, have created) a large selection of useful programs which do everything from teaching foreign languages to bookkeeping. We are still playing video games, but today's games (have become, has become) faster, more exciting interactive adventures.

17. Times have change. Computers (have become, has become) powerful machines with very practical applications. Programmers (has created, have created) a large selection of useful programs which do everything from teaching foreign languages to bookkeeping. We are still playing video games, but today's games (have become, has become) faster, more exciting interactive adventures.

18. Times have change. Computers have become powerful machines with very practical applications. Programmers (has created, have created) a large selection of useful programs which do everything from teaching foreign languages to bookkeeping. We are still playing video games, but today's games (have become, has become) faster, more exciting interactive adventures.

19. Times have change. Computers have become powerful machines with very practical applications. Programmers have created a large selection of useful programs which do everything from teaching foreign languages to bookkeeping. We are still playing video games, but today's games (have become, has become) faster, more exciting interactive adventures.

20. Times have change. Computers have become powerful machines with very practical applications. Programmers have created a large selection of useful programs which do everything from teaching foreign languages to bookkeeping. We are still playing video games, but today's games have become,faster, more exciting interactive adventures.

21. Bibliography http://www.englishpage.com/verbpage/ver bs6.htm http://www.englishpage.com/verbpage/ver bs6.htm http://web2.uvcs.uvic.ca/elc/studyzone/41 0/grammar/ppvpast.htm http://web2.uvcs.uvic.ca/elc/studyzone/41 0/grammar/ppvpast.htm http://www.ego4u.com/en/cram- up/grammar/simpas-preper http://www.ego4u.com/en/cram- up/grammar/simpas-preper