"The men have lunch at the restaurant."
Translation:Gli uomini pranzano al ristorante.
Very true.. many languages are there.. which cannot be translated to English word by word. If we translate word by word it loses its original meaning or expression. Hence I feel we must understand the way things are expressed in any new language and just learn that without giving too much importance to how it is translated to English. English is not my mother tongue .. may be that is why I feel this way.
It's all about how the verb conjugates.
Regular verbs like "pranzare" are fairly easy, although it always helps to know what the infinitive is.
For regular verbs that end with -are, -ere, or -ire in the infinitive, simply replace the infinitive ending with the appropriate conjugation ending according to the chart.
"Pranzare" is a regular -are verb, so it follows the -are pattern:
"-ire" patterns are a little more complicated because there are two templates, but I don't think Duo has covered them yet.