Here's an example. In SQL the "select" clause comes at the start. In C# LINQ queries, "select" comes at the end. A major resulting difference is autocomplete works in the latter case but not the former.

A more pervasive example is how OOP languages do x.f(...) instead of f(x, ...). This also helps with autocomplete. Also it results in calls chaining like x.y(...).z(...) instead of nesting like z(y(x(...), ...), ...).

These kinds of things have noticeable effects on how easy it is to discover relevant methods and how fast they are to type.