Adjectives with -ed or -ing
A growing number of languages are on the verge of becoming ...
- endangered
- endangering
I know that when we discuss personal feelings we should use -ed. -ing is used when we talk about things that causes these feelings.
None of the rules fit this example.
Which one should I use here?
Here's the full sentence:
As economic and cultural globalization and development continue to push forward, a growing number of languages is on the verge of becoming ... and, eventually, extinct.
The word endangering is not an adjective, though it can be a participle that functions as an adjective.
The correct word for the blank is the adjective endangered. Your example sentence should look like:
As economic and cultural globalization and development continue to push forward, growing numbers of languages will become endangered and eventually, extinct.
The verb endanger means:
Put (someone or something) at risk or in danger.
Example:
He was driving in a manner likely to endanger life.
To use the present participle endangering to form a verb tense, you must rephrase your sentence:
As economic and cultural globalization and development continue to push forward, they are endangering growing numbers of languages.
You cannot use endangering as a participial adjective to describe languages, because that would mean the languages are doing the endangering:
As economic and cultural globalization and development continue to push forward, growing numbers of endangering languages will eventually become extinct.
You can use endangering as a participial adjective to describe globalization and development, since these processes are the party responsible for putting the languages in danger:
The endangering economic and cultural globalization and development continue to push forward, and will eventually make growing numbers of languages extinct.
(Oxford Dictionaries Online)