Relative pronouns after prepositions: is it okay to use them in speech?

Question

Consider the following usages of relative pronouns: 1. The lecturer introduces a study *in which* participants were asked to choose one attractive picture. 1. At the university I met famous professors, *many of whom* were fluent English speakers. One of my grammar textbooks says that these usages are bookish. The question is whether I sound strange if I use relative pronouns in these ways in speech (I have TOEFL speaking section in mind). This may not be a relative pronoun technically, but people sometimes write *I have no pen with which to write letters* instead of *I have no pen to write letters with*. Is the former expression too formal to be used in speech?

Answer 1

Hello! I think that grammatically and historically speaking, the most accurate version is, "I have no pen with which to write." The general rule is that you should not end a sentence on a preposition ("I have no pen to write with"). However, since spoken language is constantly evolving, the fact of the matter is that most native speakers of English tend to be sloppy and break grammar rules often. In speech (as well as conversational writing), most people use the latter of the two versions you have mentioned.

All in all, I would agree that the former, although correct, is generally reserved for formal writing (academic, business, etc.), and that the latter is most commonly used in everyday speech.

I hope that helps!