Verbs show up in four forms: base, simple past, present participle, and past participle.
Study this chart and complete the last four rows.
Name of verb
Base form
Past form
Present participle
Past participle
to watch
I can watch. I watch.
I watched.
I am watching.
I have watched.
to wait
I can wait. I wait.
I waited.
I am waiting.
I have waited.
to try
I can try. I try.
I tried.
I am trying.
I have tried.
to laugh
I can laugh. I laugh.
I laughed.
I am laughing.
I have laughed.
Study the chart again. Which forms can stand alone as single-word verbs? Which ones act as main
verbs in verb strings? Draw your own conclusions before going on to the explanations of each form
below.
The base form comes directly from the name of the verb.
to watch -- watch
to wait -- wait
The base form can combine in a string with any of these auxiliaries:
Auxiliaries
Examples of Verbs Strings
can, will, shall
could, would, should
may, might, must
do, does, did
can watch, will watch, shall watch
could wait, would wait, should wait
may try, might try, must try
do laugh, does laugh, did laugh
The fireworks will scare Saeed, so probably we should go home.
He may object, but after all, he does need some sleep.
Chapter 15 will offer more work on consistency of tenses.
Sentences that express conditions and results also show a contrast in verb tenses.
If it had rained we wouldn't have had a fire drill.
TIP FOR ESL STUDENTS: Click on the ESL icon at left to visit "Conditional Sentences" for help with the way English combines tenes to express conditions and results. Practice these forms with a teacher or tutor.