Prefix · light / photography
Signals relation to light or photography: photograph, photosynthesis, photon, photovoltaic.
Written by Bryan López, English teacher · Updated
Photo- comes from Greek "phos/photos" (light) and signals a relation to light or to an image captured by light: photograph = an image written by light; photosynthesis = chemical synthesis using solar light energy; photon = a particle of light; photovoltaic = converts light into electricity. In every case, light is the central element.
Beyond photography, photo- appears throughout physics and biology: photon (the basic unit of light in quantum physics), photovoltaic (solar cell), photoelectric (the photoelectric effect, discovered by Einstein), photosensitive (reactive to light). In technology: photocopy, photomontage, phototherapy. The prefix is remarkably versatile across scientific disciplines.
Attaches to scientific and technical nouns and adjectives. Identical to Spanish foto-:
Pronunciation: /ˈfəʊtəʊ/. Identical to Spanish "foto-." "Photo" alone is the informal shortening of "photograph" in everyday English.
photo-/ˈfəʊtəʊ/
Tap the button to hear how the prefix sounds. Each word in the table has its own audio.
In informal conversation, "photo" works just like in Spanish. "Photograph" is the formal or technical form. "Photography" = the art or technique; "photographer" = the person who practises it.
Plants carry out photosynthesis whenever light is available, whether solar or artificial (such as grow lamps). The absence of light stops the process, but it is the light energy itself that matters, not sunlight specifically.
A trick to remember it
Photo- = "foto-" in Spanish: photograph = fotografía, photosynthesis = fotosíntesis, photon = fotón, photovoltaic = fotovoltaico. If something involves LIGHT, it can take photo-: photoelectric, photosensitive, phototherapy, photocopy.
Exercise 1 · Form the word
Exercise 2 · Pick the right one
"The solar panels use ___ cells to convert sunlight directly into electrical energy."
Exercise 3 · Pick the right one
What is the difference between "photo" and "photograph" in English?
The prefix photo- signals relation to light or photography: photograph, photosynthesis, photon, photovoltaic. In Spanish it usually maps to foto-.
The prefix photo- is pronounced /ˈfəʊtəʊ/. For example, "photograph".
"graph" becomes "photograph". It is a typical example of the photo- prefix.
un-, re-, pre-, dis-, over-, in-... every beginning you need to unlock thousands of English words at once.