Wendy Sumner-Winter - Intro to Science Writing

Active Verb Tenses

Simple Present
Present or Action Condition	General Truths
I hear you. Here comes the bus.	There are thirty days in September.
Non-action; Habitual Action	Future Time
I like music. I run on Tuesdays and Sundays.	The train leaves at 4:00 p.m.

Present Progressive
Activity in Progress	Verbs of Perception
I am playing soccer now.	He is feeling sad.

Simple Past
Completed Action	Completed Condition
We visited the museum yesterday.	The weather was rainy last week.

Past Progressive
Past Action that took place over a period of time	Past Action interrupted by another
They were climbing for twenty-seven days.	We were eating dinner when she told me.

Future
With will/won't — Activity or event that will or won't exist or happen in the future	With going to — future in relation to circumstances in the present
I'll get up late tomorrow. I won't get up early	I'm hungry. I'm going to get something to eat.

Present Perfect
With verbs of state that begin in the past and lead up to and include the present	To express habitual or continued action
He has lived here for many years	He has worn glasses all his life.
With events occurring at an indefinite or unspecified time in the past — with ever, never, before
Have you ever been to Tokyo before?

Present Perfect Progressive

To express duration of an action that began in the past, has continued into the present, and may continue into the future

David has been working for two hours, and he hasn't finished yet.

Past Perfect
To describe a past event or condition completed before another event in the past	In reported speech
When I arrived home, he had already called.	Jane said that she had gone to the movies.

Future Perfect

To express action that will be completed by or before a specified time in the future

By next month we will have finished the job. He won't have finished his work until 2:00.