Verb + adverb of manner vs Verb + adjective (B1-B2)

Most people wouldn't argue that we work much more effectively when we feel happily happy in our jobs.   

But when do I use an adverb and when do I use an adjective

To help you, you need to know the difference between a link verb and an action verb.

The verb 'be' is an example of a link verb. 

I'm cold.  Can you turn the air conditioning down?

I'd need to wear a coat if I worked on Reception.  It's always really cold down there!

Link verb + adjective

Link verbs can join an adjective to a subject

In other words, they tell us more about the subject of a sentence and answer the question Who...? or What...?

Who is cold? ~ I am.

What is always really cold? ~ Reception

Some common link verbs: 

Link Verb
's hot in here.  Can you open a window?
pale Are you feeling OK?
feels so humid today.  We really could do with a storm.
This water
tastes horrible! Where did you get it?
seemed annoyed after the meeting.  I don't think it went very well. 
's getting / becoming
more and more difficult to fill vacancies in our industry these days. 

Action Verb + adverb

Action verbs, on the other hand, use an adverb and answer the question How...?

How do people work when they feel happy in their jobs? ~ They work much more effectively.

Link Verbs - Who...? / What...? Action Verbs - How...?
Telling someone that they need to improve isn't effective.  You need to tell and show them how.
In the training course, he learnt to manage performance more effectively.
I'm surprised that she felt nervous during her presentation.  She always seems very confident to me. She didn't answer some of the questions very confidently.

Interested in learning more?

Other examples of link verbs are appear, remain, sound and smell

However, you need to identify the specific meaning that you want to communicate and choose either an adjective or adverb because some verbs can have both a link AND an action function.  Compare the example below. 

After Caitlin said her water tasted horrible, Paul tasted it nervously.

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