Translation:Knowing my father, we will certainly eat at that restaurant this evening.
In Italian, the present tense can be used for immediate future meaning as long as some other element in the sentence makes a clear reference to the future; in the sentence above, 'stasera' qualifies. In another source, I've read that present is allowed when future plans are definite and not tentative. See http://italian.about.com/od/verbs/a/italian-verbs-present-tense.htm.
If you are making a future prediction based on evidence in the present situation, use 'going to'.
I think this could be the reason why. source: http://www.englishgrammarsecrets.com/goingtoorwill/menu.php
Hmmm. Native American English speaker here. 'We will eat...' is fine and is now accepted by DL. 'We are going to eat...' is also fine, especially in conversation, but is kind of (sloppy) casual talking. Anytime that you want to say 'We are going to...' you could just as well say 'We will...' They are completely interchangeable.
This is not true! "We will eat" and "we are going to eat" are NOT always interchangeable. Here are two links that discuss some of the differences:
For native English speakers: imagine someone saying "Hey, I'm going to buy you a drink?" versus "Hey, I'll buy you a drink?"
The first one is impossible, except in a special case where the speaker has been instructed to buy a drink for the listener, and is informing the listener (perhaps with resignation) that they are to buy a drink for the listener, whether they like it or not ("So...I guess I'm buying you a drink?"). The second one is grammatical, and it's a generous offer that could be turned down with no difficulty.
If you want a lot more detail, English doesn't have a real future tense like many other languages. But we (including us native speakers) are often taught in school that "will" and "going to" comprise the future tense. Instead of a future tense, we have a variety of modals that can be used to express predictions, intentions, etc., which can take place in the future. Here are two blog posts that go into more detail (one of which was written by the author of the Cambridge Grammar of the English Language).
Hope this helps!