The document compares the present perfect simple tense versus the past simple tense in English. It outlines their formations, uses, and signal words. The present perfect simple is used to emphasize an action that occurred at an unspecified time in the past or its result in the present. The past simple is used to simply state a past action and emphasize the action itself rather than the result. Example signal words for each tense are also provided.

1. Present Perfect Simple
Versus
Past Simple

2. FORMATION
PRESENT PERFECT PAST SIMPLE
irregular verbs: see 2nd column of irregular verbs: form of
irregular verbs 'have' + 3rd column of irregular verbs
Example:
Example: I spoke I / you /
we / they have spoken
he / she / it has spoken
regular verbs: infinitive + ed regular verbs: form of
'have' + infinitive + ed
Example: I worked Example:
I / you / we / they have worked
he / she / it has worked

3. USE
PRESENT PERFECT PAST SIMPLE
certain time in the past just / already / not yet
Example: Example:
I phoned Mary 2 minutes ago. I have just phoned Mary.
Emphasis on action Emphasis on result
Example: Example:
I bought a new bike. (just telling what I I have bought a new bike. (With this
did in the past.) sentence I actually want to express that I
have a new bike now.)
certain event in the past whether / how often till now
Example: Example:
He went to Canada last summer. Have you ever been to Canada? / I have
been to Canada twice.

4. SIGNAL WORDS
PRESENT PERFECT PAST SIMPLE
yesterday just
... ago already
in 1990 until now / till now
the other day ever
last ... (not) yet
so far
lately / recently