以至

以至

"To the extent that" or "so that."

The phrase '以至' in this sentence denotes a result or extent derived from a preceding cause or condition, signifying that his focus on work leads directly to a consequence—neglecting family time.

他过于专注于工作，以至忽略了与家人的相处时间。

He is overly focused on work, to the extent that he neglects time spent with his family.

Here, '以至于' indicates a direct outcome or impact from the preceding situation—signaling the degree or effect of the heavy rainfall leading to flooding.

雨下得很大，以至于许多道路都被淹了。

The rain was so heavy that many roads were flooded.

In this context, '以至于' demonstrates the connection between Xiaoming's hard work and the positive results obtained in the examination, highlighting a causal relationship between the two events.

小明学习非常努力，以至于在考试中取得了优异的成绩。

Xiaoming worked very hard on his studies, so much so that he achieved excellent results in the exam.