“The illiteracy level of our children are appalling.”
George W. Bush, himself making an appalling mistake

The ending -ing when attached to a verb makes that word into an adjective meaning “to cause _____,” or “makes you feel _____”. For example, if something is interesting it causes interest, or if something is worrying it makes you feel worried. This is a well-known grammar rule, even for elementary students. What is more important is knowing which -ing adjectives are especially useful. Here is a fairly comprehensive list.

Alarming – makes you feel very worried
We are getting alarming reports of refugees being rounded up and shot.
Violent crime is increasing at an alarming rate.

Annoying – really irritates you
What’s really annoying is that we made the same mistake last time.
The annoying thing is he’s usually right.

Appalling – very unpleasant and shocking; really poor performance
The conditions in the camps were absolutely appalling.
The jokes were absolutely appalling.

Appealing – quite attractive
The building has an appealing old-fashioned charm.
We’ve tried to make the design more appealing to young people.

Appetizing – makes you want to eat it
The food wasn’t particularly appetizing.
I loved that appetizing aroma.

Astonishing – very, very surprising
He was eating his food with astonishing speed.
It’s astonishing how much the place has changed.

Baffling – very, very difficult to solve or understand
He has a rare skin condition that has baffled doctors for years.
Detectives remain baffled by these murders.

Challenging – difficult in a good way
Teaching young children is a challenging and rewarding job.
Her current job is challenging, rewarding and interesting.

Convincing – makes you believe
a convincing argument/explanation
He will demand convincing evidence before he adopts a new theory.

Daunting – a task so difficult you want to give up before you start
We are left with the daunting task of cleaning up this mess.
The trip seemed rather daunting for a young girl.

Dazzling – something very impressive to look at or watch
the dazzling midday sun
a dazzling display of football skills

Disappointing – makes you sad because it’s not what you expected
This year’s sales figures were very disappointing.
The Lakers’ loss in the playoffs was very disappointing.

Distracting – takes your attention away
I find it too distracting to work with the television on.
Please turn your music down – it’s very distracting.

Adaptado de Como Dizer Tudo Em Inglês Avançado, de Ron Martinez.