Like in English, in Portuguese we use the adverbs to modify the verb meaning. I'll try to demonstrate you with the same examples you have used. Examples: "I do hope you come here" is similar to "Eu espero mesmo que você venha aqui" ("mesmo" acts as "do" in this sentence) and "I really hope you come here" is similar to "Eu realmente espero que você venha aqui". In this sentence, the adverb "realmente" modify the meaning of the verb "esperar", like "really" modify the verb "hope" in English. Regarding your other examples: the structure is similar in Portuguese. We use the relative pronoun "quem" with the same meaning of "who" and the relative pronoun "que" playing as "that". Examples: It's George who cooked for all/ Foi George quem cozinhou para todos. It's Sunday that the ceremony is holding/ É domingo que a cerimônia é realizada. But pay attention that in these last sentences the words "who/quem" and "that/que"don't enphasize or change the verbs in the examples you write. Their function is to substitute other terms of the sentence: who/quem"substitutes "George/George" and "that/que" substitutes "ceremony/cerimônia".