suggest to do意为建议这么做，建议两个人一起做某事。
例句：Can you suggest any means to do it?
你能不能给我想个什么办法做这件事?
Can you suggest a way ( to do it)?
你能提出一个办法吗?
suggest doing意为建议做，建议接受者自己去做某事。
例句：I suggest doing it for five minutes at a time.
我建议每次锻炼5分钟。
I suggest doing something new.
我建议你做些新奇的事情。
You also use "couldn't" in a question to suggest doing something.
用在疑问句中也可用以建议做某事。
If there's something you want to do or somewhere you want to go, we suggest
doing it solo.
如果有什么事你想做或什么地方你想去，我们建议单独行动。
