Why a sewing machine is a 'máquina de coser'
English often names an object by putting an -ing word in front of it: a sewing machine, a sleeping bag, a fishing rod. Spanish turns this around. The main noun comes first, then de, then a plain infinitive that says what the object is for: máquina de coser, saco de dormir, caña de pescar.
English speakers tend to trip here in two ways. They keep the English order, or they reach for the Spanish gerund (cosiendo, durmiendo) because it looks like the -ing form. Neither works. Once you see the pattern, a whole set of everyday objects becomes easy to name, from goma de borrar to permiso de conducir.
The formula is noun + de + infinitive. Read it as "a bag for sleeping" or "a machine for sewing". The infinitive never changes, and the whole expression behaves like one noun.
la máquina de coser, el saco de dormir, el polvo de hornear.
dos máquinas de coser, tres sacos de dormir. You never add an -s to the infinitive.
una máquina de coser antigua (an old sewing machine).
Rule of thumb: when an English object name is "-ing word + noun" and the -ing word tells you what the object does, try the noun first, then de, then the infinitive.
The living room is a room for being in: sala de estar. A typewriter is a writing machine, máquina de escribir. In English it has become a single word, but Spanish keeps the full pattern.
Baking powder is polvo de hornear. A chopping board is tabla de cortar, and in much of Latin America you will hear tabla de picar.
An eraser is a rubber for erasing, goma de borrar, and chewing gum is goma de mascar. For shaving you have maquinilla de afeitar (razor), plus hoja de afeitar or cuchilla de afeitar (razor blade).
Fishing rod is caña de pescar, a treadmill is cinta de correr (a running belt), and a saddle is silla de montar (a riding seat). A driving licence is permiso de conducir or carné de conducir in Spain and licencia de conducir in much of Latin America. A boarding pass is often pase de abordar in Latin America.
Avoid máquina cosiendo. An object described by its purpose takes the infinitive after de.
Some -ing compounds use noun + de + noun instead: sala de espera (waiting room), salón de baile (ballroom), silla de paseo (stroller), traje de baño (swimsuit). You will also hear caña de pesca next to caña de pescar. The order is the same, but these words have to be learned one by one.
A few items use para, such as pastilla para dormir (sleeping pill). With para, the phrase describes what the thing is for rather than being a fixed name.
Stick to established names. Don't build new ones mechanically from English.
When English names an object with an -ing word in front (sewing machine, sleeping bag), Spanish usually flips it: main noun + de + infinitive, as in máquina de coser or saco de dormir. The first noun sets the gender and takes the plural, the infinitive never changes, and a gerund is never used.