Be able to inspire VERSUS be able to inspiring

[Jakim]

Business English Lesson, Advanced Level

ESL/EFL Test #15 "Advertising", question 3

A good team leader must be able to ......... his colleagues to face the challenge of a downturn in business.

(a) inspiring
(b) inspiration
(c) inspires
(d) inspire

Business English Lesson, Advanced Level

ESL/EFL Test #15 "Advertising", answer 3

A good team leader must be able to inspire his colleagues to face the challenge of a downturn in business.

Correct answer: (d) inspire

Your answer was: incorrect
A good team leader must be able to inspiring his colleagues to face the challenge of a downturn in business.
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Hi, here is my question:

"be able to" is a ph. why a following verb no need to add "ing"?

Jakim

[Alan]

Hi,

'Be able' to should be followed by an infinitive form. She is able to speak French = She can speak French = She has the ability to speak French.

A
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English as a Second Language
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