When you want to describe a situation where someone is repeating or emphasizing a point over and over, you can use a variety of alternatives to the phrase "hammering in." Some possible synonyms include "pounding home," "drilling in," "reinforcing," "emphasizing repeatedly," "driving home," "cementing," "fixating on," "insisting on," "reiterating," "harping on," "pressing home," and "driving home." Each of these options conveys a slightly different tone or emphasis, so choose the one that best fits the context you're trying to describe. The important thing is to avoid overusing the same phrase repeatedly, which can make your writing sound monotonous or repetitive.