from pp. 123-124

prestar to provide, to lend. prestación benefit. From Latin praestare, literally "pre" + "stand" or "to stand in front" according to one theory, implying "to bestow", "to give", "to lend". This word has cognates in all major Romance but not Germanic languages. Imagine a person standing in front of others giving away goodies. To clearly express the opposite direction of lend, i.e. borrow, you may say pedir prestado, although you may not need to if the context is clear.

abordar to approach (a person), to address (a topic); to board (ship etc.). Cognate with aboard (as in "All aboard!"). This word is not related to bordar ("to embroider").

litro liter (cognate), litre (cognate). Not to be confused with literal, litter.

maniobrar to maneuver (cognate). Mani- means "hand" (Spanish mano) and -obrar means "to work" (think of operate).

carencia lack. Cognate with caret ("^ sign"). The caret sign is used to indicate a missing (lacking) portion of text as in proofreading. See also carecer.

lástima pity, shame. Cognate with blasphemy ("irreverence toward anything sacred"). Occasionally, word-initial bl in Latin lost b when the word was inherited by Spanish. It's not clear how and why ph changed to t. If you prefer a mnemonic, try using stigma.

algodón cotton (cognate). In spite of its Arabic origin, this word and English cotton are fortunately cognates. We just need to remember al- in Arabic serves as the definite article (like the in English), which in this case was passed to Spanish but not English.

apellido surname. Cognate with appeal (in the sense of "to call upon another to decide an issue"). What's common to the two words is the sense of "call (someone)".

duelo duel (cognate); mourning, sorrow. The two meanings are completely separate; duelo is actually two words that happen to have the same spelling form. The second meaning is from dolor ("pain"). See also dolor.

mora default (finance); mulberry. The first meaning is cognate with moratorium ("delay in payment"). In the second meaning, or rather, the spelling form of a different word, it is cognate with the first part of English mulberry, mul-, with berry attached just to make a better sense. Not to be confused with morada/morado. See also morada ("dwelling") for the first meaning.

sustituir to replace. Alternatively spelled substituir. Cognate with English substitute. This word looks easy but there's a subtle difference in usage from English substitute. For example, "Sustituyo el azúcar por miel" means "I substitute honey for sugar", not the other way around. In "Las máquinas no pueden sustituir a los humanos", the meaning is simply "replace".

centenar hundred, cien, ciento (doublets). Cognate with centenary, centi- (as in centimeter, except that this prefix can also and usually does mean "hundredth").

apuesta bet (n.). apostar to bet. Cognate with English post. Prefix a- means "to", "near". To bet, you put or post valuables.

lecho bed. Cognate with litter ("bed", "portable bed", an obsolete sense). The Latin word has passed into all major Romance languages but not Germanic languages (except for the obsolete litter in English). Use a mnemonic such as "the lecherous person in bed".

gota drop (of liquid); gout (cognate). Cognate with gutter. According to etymonline.com, the gout "disease was thought to be caused by drops of viscous humors seeping from the blood into the joints". If you've never heard of this disease and don't plan to hear about it, use gutter, a real cognate rather than a made-up mnemonic, to help you remember the word: "Water drops from the gutter."

grueso thick, coarse, stout (adj.); thickness; bulk, mass (n.). grosor thickness. Cognate with gross.