“I am able to play the piano”中用了be able to词组,to之后的动词为什么不用动名词（v+ing)的形式?

“I am able to play the piano”中用了be able to词组,to之后的动词为什么不用动名词（v+ing)的形式? I am going to play table tennis t（） 首字母t,填一个单词 i am not able to fall in love with you,beacause i don't like you是什么意思 I am sorry that I () able to phone you yesterday. 请看看这句英语语法有没有错误I am not able to copy or burn the DVD.Because the DVD does not read and write,but it is able to play the movie.Maybe this DVD is in the protection of copyright.I am sorry to say I am not able to burn this DVD I will be able to为什么要用be而非I will am able to Dear Paul,It absolutely changed a lot this year that my life became much different.When I was in junior 2,I used to have so much free time that I was able to do whatever I wanted.Now I am junior 3,I almost can’t play anymore because of the big pres i will help you if i _______ A.am able B.will be able C.can be able to D.am able to I am going to play with my I am able to protect you and be fond of Sorry,I am not able to answer everything. I am able to draw 这句话对吗?She is able to sing Ok,when I want to smoke,I__smoke.A.can't B.couldn't C.am not able to D.was not abnle to I am afraid I won't be able to do the extra work.同义句I'm worrying ______ my________ to do the extra work introduce myself (吃饱了没事 各位看看有没有错句)I am bachelor a sunshine man,doesn't have any bad hobby .Then talking about my interest ,I like play bastetball and sneaker ,Of course ,I like English ,I believe everybody be able to say 初二英语（一道填空提）I am _____ I won't be able to go to the office for the next few days.另加上原因, it's the way i am,and try as i might,i haven't been able to change it.这句话怎么翻译? 谁能帮我翻译个英语句子：But it is the way I am and try as I might,I haven't been able to change it.