Greetings,

Good question it is !

1. I forgot to call you - I forgot that I was supposed to call you.It slipped my mind and I didn't call you.

2. I forgot calling you-  It is not common expression because it means I did not remember that I called you or not..

Hope it helps !

Regards,

Deepika Mantra

Hi!

The verb "to forget" can be used with either a gerund or an infinitive, but the meaning will be different.

When you use a gerund (the '-ing" form of a verb), it means that you did something, but do not remember it.

Ex: I forgot calling you yesterday.

This means: I called you yesterday, but I forgot that I did.

When you use an infinitive (the 'to ...' form of a verb), it means that you should have done something, but didn't because you forgot.

Ex: I forgot to call you yesterday.

This means: I did not call you yesterday because I forgot.

Some verbs like forget, remember, stop, or try can be followed by either a verb or an infinitive, but the meaning will be different.

Thank you for your input, Mikkel, Nate and Peachey (again).

Nate, it's not just in the USA that 'I forgot calling you' sounds like gibberish. The same applies to any English-speaking country. 

The only time we'd hear 'I forgot calling you' would be when a non-native used the gerund by mistake when trying to say 'I forgot to call you'.  And, of course, when learners come across grammar books and countless grammar sites telling them that "the two verbs 'forget' and 'remember' can be used with both gerunds and infinitives", this only reinforces the misleading idea that 'forget + ..ing' is a meaningful construction.

So, Aya, and anyone else who might have been confused by what the grammar books are telling you - please, take it from three native speakers from three continents (US, GB, Aus):

You cannot say  'I forgot calling you'. 

Yes, there is a construction where the gerund follows the verb 'forget' : we have the set phrase 'I'll never forget ....ing'. But that's all. You cannot extend the gerund use in this one phrase to apply to the use of the verb 'forget' in general.

The difference is one is wrong and two is right.

(edit - I'm wrong. sorry about that)

Sorry to disagree with all these upvotes and downvotes, but I think that @aegis is right.

If I called someone yesterday and then subsequently forgot that I'd made this call, I'd say "I forgot that I'd called you". I would never say "I forgot calling you". This sounds very wrong to me.

I'm beginning to wonder if this is a case of prescriptive grammar gone mad.  I'm aware that this construction is in some grammar books, and by analogy with "I remembered calling you", it would seem reasonable  that "I forgot calling you" would mean the opposite. If "I remembered calling you" means "I called you and then remembered about this", then, logically speaking, "I forgot calling you" ought to mean "I called you but then forgot about this", right? Yes, it ought to. But I'm not sure that it does.

Do we, as native speakers, really say I forgot calling you?