This page contains quick refreshers and self-help guides on basic English grammar.

Active voice is when the subject does the action: The researchers measured the distance.

Passive voice is when the subject is acted upon: The distance was measured.

Visit active voice vs. passive voice for a review of when to use these different forms.

Articles flow chart: This visual neatly summarizes when to use a, an, and the, depending on if the noun is specific, not specific, countable, or uncountable.

Articles with common nouns (a class, the class, an appointment)

Articles with proper nouns (the Twin Cities, Minneapolis, the University of Minnesota)

Self-study tutorial on articles and common nouns:  This interactive lesson will help you review how to use articles.

Modal Auxiliaries

Modal auxiliaries (modals) are a type of helping verb that are used with a main verb.

The following is the basic formula for using a modal in a sentence:

Subject + modal  + main verb
James   may   call.


Here is the basic formula for making a yes-no question with a modal:

Modal  + subject + main verb
Should   I   drive?


There are ten main modal auxiliaries in English.

Modal  Use Modal + Main Verb
can Expresses an ability or possibility can lift this forty-pound box. (ability)
We can embrace green sources of energy. (possibility)
could Expresses an ability in the past; a present possibility; a past or future permission could beat you at chess when we were kids. (past ability)
We could bake a pie! (present possibility)
Could we pick some flowers from the garden? (future permission)
may Expresses uncertain future action; permission; ask a yes-no question may attend the concert. (uncertain future action)
You may begin the exam. (permission)
May I attend the concert? (yes-no questions)
might Expresses uncertain future action might attend the concert (uncertain future action—same as may)
shall Expresses intended future action shall go to the opera. (intended future action)
should Expresses obligation; ask if an obligation exists should mail my RSVP. (obligation, same as ought to)
Should I call my mother? (asking if an obligation exists)
will Expresses intended future action; ask a favor; ask for information will get an A in this class. (intended future action)
Will you buy me some chocolate? (favor)
Will you be finished soon? (information)
would States a preference; request a choice politely; explain an action; introduce habitual past actions would like the steak, please. (preference)
Would you like to have breakfast in bed? (request a choice politely)
would go with you if I didn’t have to babysit tonight. (explain an action)
He would write to me every week when we were dating. (habitual past action)
must Expresses obligation We must be on time for class.
ought to Expresses obligation ought to mail my RSVP. (obligation, same as may)


Be aware of these four common errors when using modal auxiliaries:

  1. Using an infinitive instead of a base verb after a modal

    Incorrect: I can to move this heavy table.

    Correct: I can move this heavy table.

  2. Using a gerund instead of an infinitive or a base verb after a modal

    Incorrect: I could moving to the United States.

    Correct: I could move to the United States.

  3. Using two modals in a row

    Incorrect: I should must renew my passport.

    Correct: I must renew my passport.

    Correct: I should renew my passport.

  4. Leaving out a modal

    Incorrect: I renew my passport.

    Correct: I must renew my passport.


Modals and Present Perfect Verbs

The present perfect verb tense describes a continuing situation or something that has just happened. (I have helped. He has spoken.)

When a sentence contains a modal before the verb, the helping verb is always have.

  • I could have helped.
  • You might have arrived earlier.
  • He may have gotten lost.
  • She should have eaten before the meeting.

Be aware of the following common errors when using modal auxiliaries in the present perfect tense:

  1. Using had instead of have

    Incorrect: Jamie would had attended the party, but he was sick.

    Correct: Jamie would have attended the party, but he was sick.

  2. Leaving out have

    Incorrect: Jamie would attended the party, but he was sick.

    Correct: Jamie would have attended the party, but he was sick.



Taken from Writing for Success by University of Minnesota, licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.


Proper nouns are names of things, places, or people and should be capitalized (The University of Minnesota, Saint Paul, Jessica McDonald).

Common nouns are words that represent things, places, or people. They are not capitalized because they are not names (university, city, woman). Common nouns are either countable or uncountable.

Countable nouns can be single or plural. We can use numbers and quantity words to describe the amount of countable nouns:
one university, 4 universities
a city, many cities
one woman, some women
a pencil, a lot of pencils
one phone, a few phones
one student, few students

Uncountable nouns are always used in the single form (we never add -s to them). We can't use numbers to describe the amount of uncountable nouns, but we can use some quantity words:
some information
tons of homework
a lot of money
a little advice
little patience
not much time

This flowchart summarizes different kinds of nouns and how to use articles with them.

Parallelism is when you use the same parts of speech in a list or sentence:

  • I like biking, swimming, and studying English.
  • I like to bike, swim, and study English. 
  • Minnesota is known for its plentiful lakes and cold winters.  

The University of Minnesota Center for Writing offers a helpful quick guide to parallelism.

Preposition like in, on, at, to, and with can be one of the most challenging parts of grammar to master in English.

The University of Minnesota Center for Writing offers a helpful quick guide to prepositions.

The University of Minnesota Center for Writing has several resources to help you correctly use punctuation in your writing:

Are your sentences too short? Too long and complicated? Not connected well? The University of Minnesota Center for Writing can help you fix:

Subject-verb agreement means making sure the verb you use matches the subject. For example:

  • I study.
  • He studies.
  • We study.
  • Everyone studies.

The University of Minnesota Writing Center has a quick guide to familiarize you with subject-verb agreement.

Not sure if you should use simple present, simple past, present perfect, or past perfect? The University of Minnesota Center for Writing has advice on verb tenses. They also have an overview of verb forms that includes regular verbs, irregular verbs, infinitives (to study, to watch), gerunds (studying, watching), and modal verbs (can, could, should, etc.).

The Verb Tenses chapter of Writing for Success can also help remind you about different verb forms in English, such as

  • simple present (I study)
  • simple past (I studied)
  • future (I will study; I am going to study)
  • present perfect (I have studied)
  • past perfect (I had studied)
  • future perfect (I will have studied)
  • present progressive (I am studying)
  • past progressive (I was studying)
  • future progressive (I will be studying)
  • present perfect progressive (I have been studying)
  • past perfect progressive (I had been studying)
  • future perfect progressive (I will have been studying)

Phrasal verbs like hang outsit down, and turn off are very common in English. Visit the phrasal verbs section of our Vocabulary page for explanations and practice activities with these verbs. 

If you're not sure what form of a word to use, Word Hippo might help. Click on the Word Forms tab. Enter the word you're struggling with, and select what form you are looking for from the drop-down menu. You can search for plural, singular, past tense, present tense, verbs, adjectives, adverbs, and nouns.

For example, if you are looking for a verb for patience but can only think of the noun patience, this tool can help you find "be patient," as well as other related verbs like "accept," "bear," or "endure,"