from pp. 30-32

fácil easy, facile (cognate). Also cognate with facility (in the sense of "being facile or easy"), facilitate ("to make easy").

mayo May (cognate). It's unlikely you never heard of "Cinco de Mayo" ("May 5th Celebration", which celebrates Mexican army's victory over the French forces on May 5, 1862).

plazo term, time limit, period; installment. Cognate with placid, please ("to make happy"). From Latin placitum ("public court"; "decree"). An implied sense is the day or period the court approves or deems appropriate. But this etymology is a long shot as a memory aid. Maybe a mnemonic works better, such as "They have a long-term contract to manage this plaza."

mantener to maintain (cognate), to keep. From Latin manu ("with the hand") + tener ("to hold").

enero January (cognate). Loss of the initial j- on an unstressed syllable, which existed in Old Spanish, is characteristic of Spanish evolution.

volver to return, to roll, to turn. vuelta return, turn, lap (n.). Cognate with the root of revolve, involve. Consider the fact that Volvo, the car maker, takes its name from this Latin name meaning "I roll".

cuadro frame; painting; square (cognate). See also cuadrado ("square").

atrás behind; back (position); ago (time). From a + tras ("after").

película film; movie. From Latin pellis ("skin"). Cognate with peel, pellicle ("a thin layer supporting the cell membrane", a biological term), pillion, pelt. This word has both meanings of film, "layer" and "movie". Of all cognates, peel may be the best memory aid since it reminds of a thin film.

puerto port (cognate), harbor. Don't confuse it with puerta ("door").

fuego fire. If you've heard of the famous Brazilian restaurant "Fogo de Chão", literally "fire on the ground", use that to help remember the word, since the Portuguese word fogo is a cognate. Otherwise, focus is the Latin word ("hearth", "fireplace") which both fuego and English focus are derived from. Note that fuego is generally not used to refer to uncontrolled fire such as house or forest fire; that would be incendio. See also incendio.

local local (adj.) (cognate); premises, rooms. Note the second meaning, which is missing in English local.

sala room, hall. Cognate with salon. The -on part is a remnant of the augmentative suffix when the word was in an intermediate language in evolution; salon is literally "large room". Note that English salad is ensalada in Spanish, unrelated to sala.

cámara room, chamber (cognate); camera (cognate). To recognize chamber as a cognate, remember English ch- is sometimes pronounced k- (as in Christmas). Note this word can also mean "camera" because English camera is from a "New Latin" term camera obscura ("dark chamber or room"); before the age of digital photography, a dark room was an essential part of this technology.

vía way, road. Cognate with via. This word is easy but note the vowel í, while in other words it's not accented, e.g., viaje.

mirar to look. mirada look (n.). Cognate with mirror and the root of admire.

suerte luck. Doublet with sorteo ("raffle", "lottery"). Cognate with sorcery. If that's hard to think of, use a mnemonic such as "One achieves scientific discoveries by sweat and luck". See also sorteo. [2020-07 Update: In the revised edition, this is added: "cognate with sorcery, and sortie, which came from French meaning “an attack made by troops coming out from a position of defense”. The basic meaning is “coming out”. Raffle or lottery is basically a drawing game in which you draw a ticket out of many."]

llamar to call, to claim (cognate). One of the changes from Latin to Spanish is cl- to ll-.

prueba proof (cognate); exam; trial. To see the cognation, consider the phonetic merger of b and v, and the fact that v and f are both labiodental fricatives. The sense of "exam" is natural in that an exam proves that a student has learned something.

sueño dream; sleep (n.). From Latin somnus ("sleep"). Cognate with the root of insomnia, where in- is for negation. Latin stressed short o usually changes to diphthong ue in Spanish.

capaz able, capable (cognate).

adelante come in!, go ahead! (interj.); forward. adelantar to advance. Removing all the prefixes of adelante, you get ante, meaning "front".

ciencia science (cognate).

asunto matter, issue. It's cognate with English assumption or (what is) assumed, but is close to the English word only in one sense, i.e., "taking on a duty", not "hypothesis". Consider asunto to be a person's responsibility or duty, something to handle.

oro gold. If you don't know any other Roman language, remember the symbol for chemical element gold is Au. If you don't remember that, remember one theory for the name of the famous Oreo cookies is that Oreo comes from the French word Or (cognate), meaning "gold". In fact, Oreo cookies do look kind of dark golden.

dolor pain. doloroso painful. doler to hurt, to ache. Dolor has entered English vocabulary, but may be too literary for people to know. If you don't know it, use a mnemonic such as "Life is hard. Even making one dollar is a pain."