para decirle que llegaría tarde

to tell them they'd be late

→ para
phrase Rare #45,053
to tell them they'd be late The pronoun le can refer to him, her, or a formal you; the context determines who would be late.
SP: Llamé a Ana para decirle que llegaría tarde.
EN: I called Ana to tell her I'd be late.

Jane llamó a Mary para decirle que llegaría tarde.

Jane called Mary to tell her she would be late.

Ella le llamó para decirle que llegaría tarde.

She called him to tell him she would be late.

Él llamó a Mary para decirle que llegaría tarde.

He called Mary to tell her he would be late.

Ella lo llamó para decirle que llegaría tarde.

She called him to tell him she would be late.

Tom llamó a Mary para decirle que llegaría tarde.

Tom called Mary to tell her he would be late.

Tom llamó a María para decirle que llegaría tarde.

Tom called María to tell her he would be late.