have problem后加动词什么形式?

动词的ing形式
have problems 后面的动词要用 ing 形式,比如
My English is so poor I often have problems understanding what the teachers says.
It's so noisy here that we have problems hearing the announcement.
have problems 要接名词短语,所以用 动词+ing 形式.
注：problems 有 s .
我是加拿大人,英语是我第一语言.