afterwards 的意思是 at a later time，根据不同的语境可译为“以后”“后来”“随后”“事后”“然后”“等会儿”等。你的句子意思是：老师随后会发表讲话。（当然根据不同的上下文也可以有其他的翻译）。Afterwards 可以连用多种时态和句式。如：

1. 一般过去时

Afterward they had lunch in the garden. 在这之后他们在花园里吃了午饭。

We all had a great laugh about it afterwards. 后来我们为这件事都大笑了一通。

2. 一般现在时

I usually go to bed at nine o’clock and go to sleep ten minutesafterwards. 我通常是九点上床睡觉，并且在10分钟后入睡。

Do we try and prevent problems or do we try and pick up the piecesafterwards? 我们是想要防患未然呢，还是想要事后收拾残局？

3. 一般将来时

I’m busy now. I’ll go there afterwards. 我现在很忙，待会儿再过去。

Some people act regardless of what will happen afterwards. 有些人行事不管后果如何。

4. 祈使句

Let’s go to the theatre first and eat afterwards. 咱们先去看戏，然后再吃吧。

Don’t have a meal and bathe immediately afterwards. 不要就餐之后立即游泳。

5. 连用情态动词

Afterwards you can talk to whoever you like. 然后，你就可以同你乐意交谈的人说话。

Write down those ideas. We can discuss them afterwards. 把这些想法记录下来，我们以后可以展开讨论。