be动词后面必定加ing吗？还有什么情况（like除外）

be动词(is.am.are).介词后面加ing形式。还有固定的词组搭配要记住
某些动词后出现非限定性动词时只能用动名词作宾语，不能用不定式。常见的此类动词有：advise, allow, permit, avoid, consider, enjoy, finish, give up, cannot help, imagine, include, keep, keep on, mind, miss, put off, delay, practise, resist, suggest, depend on, think about, set about, succeed in, worry about, burst out, insist on, can’t stand, be used to, get used to, devote…to…, look forward to, pay attention to, get down to等。如：

They went on walking and never stopped talking. 他们继续走，说个不停。

I found it pleasant walking along the seashore. 在海滩上走真是乐事。

（2）作介词的宾语

We are thinking of making a new plan for the next term. 我们正考虑为下学期制定新的计划。

Shall we have a rest or get down to doing our work? 我们休息呢还是开始干活？

（3）作形容词的宾语

The music is well worth listening to more than once. 这种曲子很值得多听几遍。

We are busy preparing for the coming sports meet. 我们正为马上到来的运动会忙着做准备。

3、作表语

动名词作表语时句子主语常是表示无生命的事物的名词