Grammar: adjectives after verbs
Elementary to advanced level English (A2-C2)

You will know sentences like ‘She is happy.’ but there are other verbs that can have adjectives following them eg ‘They look afraid.’.

A common mistake is to put an adverb after some verbs when the verb has the meaning of changing or not changing:

‘The large crowd fell silent as Nelson Mandela started speaking’ is correct and means the crowd of people became quiet.

BUT ‘The large crowd fell silently as Nelson Mandela started speaking’ is not correct because it means the crowd fell over on to the ground!

Verbs that can have the meaning of changing or not changing:

Change:
I’m getting older
It’s getting warmer. Other adjectives you could use include: milder, windy
The leaves are turning red or The weather has turned rather cold
She’s becoming angry. Other adjectives you could use include: well-known, corrupt, lazy
He went crazy
I ended up frustrated (meaning eventually became). Other adjectives you could use include: lost, rich, happy
The people fell silent after hearing the bad news

No change:
I kept cool. Other adjectives you can use include: relaxed, focussed
She shop remained empty for months
We stayed calm. Other adjectives you could use include: upset, relaxed

Also there verbs which are connected with your senses eg

The meal tasted great (or fabulous, awful)
You smell lovely. Other adjectives you could use include: gorgeous, fragrant
It feels cold. Other adjectives you could use include: chilly, humid, damp
Your idea sounds fantastic. Other adjectives you could use include: brilliant, rather expensive, interesting
They looked happy.  Other adjectives you could use include: depressed, moved, interested

Other examples

His sister appeared calm (or agitated, angry)

When you are reading, try to notice when verbs and adjectives are used in this way.