Like vs As Exercises

Like and as both express comparison or similarity, but they follow different grammar rules. Like is a preposition meaning "similar to" — it is followed by a noun or pronoun: "She sings like a professional," "It looks like rain." As has two main uses. As a conjunction, it introduces a clause (with a subject and verb): "Do as I say" (in the way that I say). As a preposition describing a role or function, it means "in the position of": "She works as a nurse" (her job is a nurse, not similar to a nurse).

The most important difference is between "like" (similarity) and "as" (actual role). Compare: "He spoke like a lawyer" (not a lawyer, but spoke similarly) versus "He spoke as a lawyer" (actually a lawyer, speaking in that role). Fixed expressions include "as usual," "as always," "such as" (for examples), and "as if" / "as though" (imaginary comparisons). A common mistake is using "like" before a clause in formal English: "Like I said" is informal — in formal writing, use "As I said." This distinction is tested in Cambridge B1 and B2 examinations.