Why isn’t “running late” a phrasal verb?

This is a very common mistake arising due to a little confusion.

A phrasal verb is a verb that consists of a verb and another element. This other element that follows the main verb is typically a preposition or an adverb. This addition of the other element can also change the meaning of the verb. For example, the word count means to determine the total sum, but the addition of the preposition on makes the phrasal verb count on, which means to rely on something or someone.

But in 'running late,' late is an adjective rather than an adverb or preposition & thus 'running late' is not a phrasal verb.

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