Verbs: formation with common prefixes and suffixes

 

We can make new words by adding prefixes and suffixes to words we already know.

 

Prefixes go at the beginning of words. We use prefixes to change the meaning of words, including verbs:

• Alex decided to rewrite his paper to get a better grade.
• Why did you undo all of the work I did on the website?  Now I have to redo it all.
• I think you should disconnect the printer and then reconnect it.  That might work.
• You have to preorder items so that you get them on time.

 

The most common verb prefixes and their meaning:

 

Prefix	Meaning	Examples
re-	again or back	restructure, revisit, reappear, rebuild, refinance
dis-	reverses the meaning of the verb	disappear, disallow, disarm, disconnect, discontinue
over-	too much	overbook, oversleep, overwork
un-	reverses the meaning of the verb	unbend, uncouple, unfasten
mis-	badly or wrongly	mislead, misinform, misidentify
out-	more or better than others	outperform, outbid
co-	together	co-exist, co-operate, co-own
de-	do the opposite of	devalue, deselect
fore-	earlier, before	foreclose, foresee
inter-	between	interact, intermix, interface
pre-	before	pre-expose, prejudge, pretest
sub-	under/below	subcontract, subdivide
trans-	across, over	transform, transcribe, transplant
under-	not enough	underfund, undersell, undervalue, underdevelop

 

Note: You may see verbs with prefixes written with a hyphen (-).  This happens when a verb is not commonly used with a prefix, such as: ‘re-submit’.  This will also depend on the type of English (American or British).

 

Suffixes go at the end of words. We use suffixes to change a word, like a noun or an adjective, to a different type of word, such as a verb.  

• The butter is very soft because of the heat. – The butter softens when it is hot.  

‘Soft’ is an adjective, and it changes to a verb when we add ‘-en’.

 

Another example is ‘-ise’, which turns nouns to verbs.

• I find it hard to sympathise with you because my life is so different.  
• We should try to synthesize all of this information so that it is easier to understand.

 

The most common verb suffixes and their meaning:

 

Suffix	Meaning	Examples
-en	To become	Soften, darken, widen, weaken, strengthen
-ise/-ize	To make or become	Sympathise, empathise, synthesize
-ate	To become	Activate, collaborate, create
-ify, -fy	To make or become	Justify, magnify, amplify, satisfy

• Nowadays students need to learn how to collaborate on projects.
• You should use clear arguments to justify the opinions in your essay.  

 

Note: It is important to be able to identify the root word or base word. This will help you create new words, such as ‘justify – justice – justification – just – justly’. The root word is often the verb and then other words, like nouns, adjectives, and adverbs, are created with it, like ‘create – creative – creativity’.

 

Modal verbs: suggestions and advice

 

To give suggestions and advice we can use the modal verbs ‘could’, ‘should’, ‘ought to’, ‘had better’.

 

‘Should’ is used when the speaker wants to make a strong suggestion:

• The sun is shining bright, so you should wear a cap.
• You look pale. I don’t think you should go to school today.
• The road is wet. You shouldn’t drive too fast.

 

In more formal situations you can use ‘ought to’ instead of ‘should’, but this modal verb is not used in negative statements and questions:

• You ought to (should) wear a scarf. It’s very cold outside.
• They ought to hurry, their train is leaving.
• Jane ought to visit that castle, it’s great!

 

Note: Both ‘should’ and ‘ought to’ are used to express advice, obligation or duty. BUT: ‘should’ is used when we want to express our subjective opinion. In other words, ‘what I think is best for you to do’. You should call your mother more often. ‘Ought to’ is used when we want to express an objective truth. In other words, ‘what is necessary, and cannot be avoided’. That’s why we usually use ‘ought to’ when we are talking about laws, duties and regulations. They ought to follow the school’s policy, or they will get expelled.

 

If you want to give an important piece of advice or recommendation (that can have a negative consequence if not followed), use ‘had better’:

• You had better (You’d better) leave for work, it’s 8 o’clock already.
• We’d better go that way, we’ll save about 10 minutes.
• He’d better park his car correctly or he will get fined.

 

Note: Had better is a strong expression. We use it if we think there will be negative results if someone does not do what is desired or suggested.

 

‘Could’ is not as strong as ‘should’ and is normally used to give mild advice or to suggest a solution to some problem:

• – I hate my old jeans!
• – Well, you could buy a new pair.

 

• If they need more space, they could look for a bigger house.
• Jack moves to Canada next month. He could learn to play hockey there.

Modal verbs: obligations, negative and questions

 

In negative statements ‘must’ and ‘have to’ are used differently.

 

‘Must not’ is a negative obligation, meaning that something is not allowed.

 

We form negative statements with ‘must not’ like this:

 

Subject + must not + the verb (base form without ‘to’):

 

Singular	Plural
I must not (mustn’t) speak You must not speak He/she/it must not speak	We must not speak You must not speak They must not speak

• She must not take this medicine.
• You must not smoke in the office.

 

‘Do not have to’ is used when there is no need to do something.

 

We form negative statements with ‘do not have to’ like this:

 

Subject + do not / don’t / doesn’t have to + the verb (base form of the verb):

 

Singular	Plural
I do not (don’t) have to wait You don’t have to wait He/she/it doesn’t have to wait	We don’t have to wait You don’t have to wait They don’t have to wait

• You don’t have to buy me a birthday present.
• It’s summertime, and Peter doesn’t have to go to school.

 

We also use ‘have to’ in questions, for example, to ask if something is necessary. Such questions are formed like this:

 

Do / Does + subject + have to + infinitive form of the verb:

 

Singular	Plural
Do I have to speak? Do you have to speak? Does he/she/it have to speak?	Do we have to speak? Do you have to speak? Do they have to speak?

• Do I have to get ready now?
• Does she have to leave before 12 a.m.?

 

Note: ‘must’ is possible for questions, for example: Must we finish this today? But it is not as common as ‘have to‘.

 

Modal verbs: possibility

 

We can use modal verbs to talk about possibility or to express uncertainty. The most common modal verb for such cases is ‘might’.

Statements with ‘might’ can refer to past, present, or future possibilities.

 

1. To refer to past possibility, use:

Might + have + Past Participle

(for regular verbs, this is the “-ed” form of the verb. See more in Participles section)

• I can’t find my pen. I might have dropped it earlier.
• We are lost. We might have taken a wrong turn at the river.

 

2. To refer to present possibility, use:

Might + the verb (base form without ‘to’)

• Look at Jack! He might be in a hurry to meet with Catherine.
• The clouds cover the top of the mountain. It might be windy there.

 

3. To refer to future possibility, use:

Might + the verb (base form without ‘to’) + future time marker

• It’s cold outside. It might snow later on.
• Joe might not come to our party next weekend.

 

Modal verbs: making deductions

 

We can use modal verbs to talk about probability or improbability of something, as well as to make deductions about some facts or events.

 

To talk about something with uncertainty, use modal verbs ‘might’ and ‘could’:

• Sarah isn’t feeling well. She might have a cold.
• I have a high temperature. It could be a flu.

 

To describe negative things you are not certain about, use ‘might not’:

• Your leg is not swollen, so it might not be serious.
• I can’t reach Tom by phone, he might not be in the city.

 

To speak with more certainty about things in present, use ‘must’:

• John must be very tired, he’s been staying in bed all day long.
• They must be absent, I cannot find them anywhere.

 

To speak about something you consider absolutely impossible, use ‘cannot (can’t)’:

• Jack cannot be at school, I saw him playing basketball at the playground.
• Pete’s leg can’t be broken, he walked to the doctor without any help.

 

To speak about something that you think definitely happened in the past, use  ‘must have’ with the Past Participle (for regular verbs, this is the “-ed” form of the verb. See more in Participles section):

• I can’t find my socks. My wife must have taken them to the laundry room.
• Nobody opens the door, my friend must have left the house already.

 

In case you are not sure whether something happened in the past, use ‘may have’, ‘might have’ or ‘could have’ instead of ‘must have’:

• Cindy didn’t return my call yesterday. She might have forgotten to call me back.
• I didn’t see who knocked on the door, but it may have been the postman.

 

And finally, to speak about something you are absolutely sure did not happen in the past, use ‘couldn’t have’:

• I saw a flash in the sky, but it couldn’t have been aliens, they don’t exist.
• Paula couldn’t have been at the party last night, she was at work.

Present Perfect or Present Perfect Continuous?

 

How do you choose between the Present Perfect Continuous and Present Perfect?

 

The Present Perfect Continuous is used to show that an activity in the past was in progress. It is possible that the activity is still taking place.

• We’ve been looking at those beautiful paintings for two hours.

 

The Present Perfect is used to show that an activity in the past is finished.

• We’ve selected our favorite painting among those exhibited.

 

Consider the following examples:

 

Present Perfect Continuous

I’ve been cooking dinner. It will be ready soon.

Jane’s been running today. Now she’s really tired.

We’ve been eating too much cake. We must eat less.

 

Present Perfect

I’ve cooked dinner. It is ready now.

Jane has just run a race. Now she’s receiving a medal.

We’ve eaten all cake. The plates are empty.

 

Present Perfect Continuous: questions

 

To make questions in the Present Perfect Continuous, put have/has before the subject and add been + the “-ing” form of the verb:

 

Singular	Plural
Have I been reading? Have you been reading? Has he/she/it been reading?	Have we been reading? Have you been reading? Have they been reading?

 

• Have you been watching the movie?
• Yes, come in, let’s watch it together.

 

• Has she been studying French this year?
• Yes, and she is taking her exam next Monday.

 

• Have they been waiting for the bus for an hour?
• Unfortunately… Looks like the bus broke down.

Present Perfect Continuous: negative

 

To make negative statements in the Present Perfect Continuous, use have/has not (haven’t/hasn’t) + been + the “-ing” form of the verb:

 

Singular	Plural
I haven’t been running You haven’t been running He/she/it hasn’t been running	We haven’t been running You haven’t been running They haven’t been running

• I haven’t been eating all day long. I am very hungry.
• Vicky hasn’t been sleeping last night and now she looks drowsy.
• We haven’t been talking to each other since last Friday.

 

 

 

Present Perfect Continuous: statements

 

We use the Present Perfect Continuous to talk about a continuing activity in the past that still influences the present moment.

 

This activity might just have stopped or might still be happening:

• I have been painting the house all day. I am exhausted (past activity affects the present moment).
• He’s been fixing his car. He’s covered in oil (while fixing is still taking place).

 

To make the Present Perfect Continuous, use have/has + been + the “-ing” form of the verb:

 

Singular	Plural
I’ve been skating You’ve been skating He/she/it’s been skating	We’ve been skating You’ve been skating They’ve been skating

• I’ve been cooking this evening. Now I have to do the dishes.
• Jane’s been running her first marathon today, and she is very happy with her net time.

 

Past Continuous: questions

 

To make questions in the Past Continuous, put ‘was/were‘ before the subject and add the “-ing” form of the verb:

 

Singular	Plural
Was I singing? Were you singing? Was he/she/it singing?	Were we singing? Were you singing? Were they singing?

• Was it snowing yesterday at 5 o’clock?
• Were you still skating in the park when Jemma called you?
• Were the boys working in the garden when their uncle came round for a coffee?  

 

Note: in short positive answers to the Past Continuous questions we use only full forms of was/were. In short negative answers we can also use short forms of was/were.

 

• – Yes, he was (No, he wasn’t).
• – Yes, I was (No, I wasn’t).

 

• – Was he playing football at that moment?
• – Yes, he was (No, he wasn’t).

 

• – Were they staying with their parents?
• – Yes, they were (No, they weren’t).