Suggest means to "put forward for consideration" Advise means to "offer suggestions about the best course of action to someone." Recommend means to "put forward (someone or something) with approval as being suitable for a particular purpose or role." To clarify, to advise means you are suggesting an action to someone, recommend means that a person finds something suitable and they suggest it, and suggest is the action of putting an idea out to others for consideration. Hope this helps!

They all practically mean the same thing. "I suggested the restaurant for their date." "I advised them to meet at the restaurant for their date." "I recommended the restaurant to them for their date." The only real difference here is how the sentence is structured when using the words. Suggestions, advice, and recommendations are all courses of action being offered to someone.

they are very similar. I think you would have to provide examples in sentences and maybe depending on the context, one might be preferred over the others.