"I eat a sandwich."
Translation:Ik eet een boterham.
This is diffrent conjugation for the verb. There are rules for how any verb should be changed for each subject (Ik, Je, Ze (she), Hij, Het, Ze (they),We, Jullie and U). I'm not sure about all of them for the verb eten, but for Ik, Hij, Je and Ze (she) it's eet and for Ze (they), We and Jullie it's eten. You can find the rules in tips.
There is nothing oldfashioned about a boterham!! It's the normal everyday life thing people eat at home.
If you only eat out and never make your own lunch you will come across broodje but that is something different.
Boterham=single slice of normal bread with usually a simple topping, like a couple of slices of cheese or some jam. (without a topping it's still a boterham)
Broodje=more exotic types of bread usually not squishy like normal bread. So foccacia, ciabatta, baguette, petition pain etc. Sliced open and filled with a lot of stuff almost always including greens like lettuce and cucumber. And often tomatoes and nuts walnuts and pine nuts usually.
Another big difference is a Boterham will cost you 10 cent max (so 0.10) een broodje will cost about 7.50 (I lf you were to duplicate thus at home the cost will obviously be lower I guess for around 1.50 you could make it work. Either way atleast 10x as much)
You won't find boterham on most menus unless it's a place that wants to offer something simple and familiar to kids (I've seen it a couple of times but it's a rarity). But millions of boterhammen is what people eat everyday. (16 million people, most eat atleast two boterhammen a day... (eating 6 is rather normal for some 2 in the morning 2 at lunch and 2 at another break if the place your work doesn't have its own canteen
No boterham is the normal word for what you eat at home. Only if you are at a restaurant you wouldnt use the word Boterham (because that is not what you are getting)
Honestly imo all these sandwich questions should be replaced, it gives people the wrong idea. The three aren't the same.
Like if in the Italian course a pizza would be translated with sandwich (imagine ... I know it's tough.. america didnt have pizza and most hadn't heard of it yet) both are made of dough. Would you really call a pizza a sandwich? If not why call a boterham one.