Thank you very much! :-)

I hope <em>to write</em> in the correct form in my next discussion

Not really a trick but once a student told me she noticed that things connected to the past took -ing and things connected to the future took -to do .For example "hope" "plan","want" are all looking to the future, so they take infinitive.I remember doing, I was used to doing look to the past.It is not 100% true but it kind of helps a bit.

If the could be replaced by a noun, then a gerund is always possible. That will help you figure it out in a lot of cases.

Otherwise, it's just random.

*If the <em>verb</em>

No, there isn't a trick, I'm afraid. All you can do is try to absorb as much English as possible until you know instinctively which form sounds right. Native English speakers don't learn rules, we just hear and copy.

It's also worth remembering that there are a few verbs for which you can use either a gerund or infinitive and it makes no difference ( e.g. start) and, more importantly, some where the use of the gerund or infinitive totally changes the meaning ( e.g. try, remember).

By the way, I couldn't help noticing the similarity in your photos, Vivianna and Ruthi. The same nice smiles! You could be sisters.