To sum up, never use the verb call with “to”!
you can call me, him, her, your friend, your brother, your Client, the fire department, the police, a doctor, an ambulance, a taxi, an office.
But you cannot call to them!
Similarly, you call somebody back!
Usage note: phone / call / ring
Verbs: In British English, to phone, to ring and to call are the usual ways of saying to telephone. In North American English the most common word is call, but phone is also used. Speakers of North American English do not sayring. Telephone is very formal and is used mainly in British English.
Nouns: You can use call or phone call (more formal) in both British English and North American English:Were there any phone calls for me? ◇ How do I make a local call? The idiom give somebody a call is also common:I’ll give you a call tonight. In informal British English you could also say:I’ll give you a ring tonight.
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