Have a look at this : http://www.collinsdictionary.com/dictionary/english-cobuild-learners/suggest?showCookiePolicy=true "suggest" can be used in various ways, as the dictionary definition indicates.In your case, you have two ways of saying the same thing: 1. "He suggested (to her) that she relieve her stress by taking exercise." subject + suggest + that + main clause (NB no -s in third person singular present tense - subjunctive tense) 2. "He suggested exercise (to her) (in order) to relieve her stress" subject + suggest + object + infinitive Both phrases are equally good but you can see that the second one is shorter.