the cell phone v.s. cell phone

[Lost_Soul]

Hi, everyone

I’m out of the office. I’m available via cell phone

I’d like to ask you if I need to add any article before cell phone, if I just want to convey to the listener the way through which I’m available, I dont want to specify any particular phone.

Thank you in advamce

[Mister_Micawber]

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No, no article-- then you’d have to choose among a, the, my…
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[Tom]

@Mister Micawber

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No, no article-- then you’d have to choose among a, the, my…
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Thank you, MM

Please answer this one too. Are all correct and natural and carry the same meaning?

You could have called me there only–what are cell phones for?

or

You could have called me there only–what is a cell phone for?

or

You could have called me there only–what is the cell phone for?

Tom

[Mister_Micawber]

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Yes, but ‘What’s a / What’re…’
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[Tom]

@Mister Micawber

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Yes, but ‘What’s a / What’re…’
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I am grateful, MM!

…but why are contractions necessary?

Tom

[Mister_Micawber]

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They aren’t, but you asked for naturalness.
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