Learn the key differences and proper usage of which and in which , two relative pronouns that connect clauses in English. Find out when to use which to add information or in which to show location or context, and see examples and exercises. Learn how to use prepositions with relative pronouns such as in which , of which , at which , and to which to indicate a relationship between two clauses. See examples, explanations, and tips for formal and informal English. Have you ever paused mid-email, wondering if it’s correct to say “by which” or “ in which ”? You’re not alone. Even seasoned professionals in business communication, project management, and academic writing stumble over these subtle grammatical choices. In formal contexts—like scheduling meetings, online booking systems, or broadcasting calendars —choosing the right preposition can make your sentence sound polished or awkward. That’s why understanding the difference between ... Are you an inspiring writer or student trying to complete an essay? There are plenty of tricky words and phrases in everyday English, like their, there, or they’re, and who vs whom. One you might also get stuck on is when to use where vs. in which . Keep reading to figure out which one to use when!
