The Spanish flojo means “slack, loose” — but it is a very common word in Spanish, often used to mean “relaxed” in a negative way, in senses like, “They cut themselves some slack.”
Flojo comes from the Latin fluxus, meaning the same as the Spanish. From fluxus, we get a bunch of English words, including: fluent, fluid, fluctuate and even (via fluent) affluent and influence. We also get the more fun flush and the most obvious flux (as in, “to be in flux.”) All of these can be understood in the sense that, that which is loose flows — and all of these words flow in one way or another: liquids are fluid, you speak fluently, flushing water flows, money flows if you are affluent, etc.
The ‑x- in the original Latin tended to disappear into the English (hence leaving the vowels before and after, as in fluent or fluid) or became a ‑sh- sound. This is an example of the common pattern of the ‑sh- sounds mapping to the throat-clearing ‑j- in Spanish, with the fl-sh of flush mapping to the fl‑j of flojo.
Quejar, Spanish for “to complain” doesn’t seem related to any English equivalent.
But upon closer look, it is a first cousin of both quash and squash.
All come from the Latin quassare, meaning, “to shatter.”
The relationship is easy to see if we remember that the Spanish ‑j- sound used to be the Latin ‑s- sound (and many variants, like ‑ss‑, ‑si‑, ‑sy‑, ‑sh‑, ‑ch‑, etc).
Thus, the qu‑j for quejar maps to the qu-sh of quash and the sq-sh of squash.
Complaining, it seems, is a form of quashing (squashing?) your opponent!
Perejil and its English version parsley sound very different. But they are, actually, etymologically the same word.
They sound different because often the ‑s- and ‑sh- sounds in Spanish turned into the letter ‑j- with the Arabic throat clearing sound as a pronunciation. Thus, the p‑r-j‑l of perejil maps exactly to the p‑r-s‑l of parsley.
The Spanish bajo, for “low”, sounds unlike the similar words in English.… except for base.
Think about base as the core foundation or support — the lowest thing holding everything else up — or even in the old Shakespearean sense of “vile”, “the basest weed” — the connection makes much more sense.
Both come from the Latin basis (meaning, “foundation”) — from which we also get the same English, basis.
And think of the bass cleff in music, for the lower notes, as well.
The surprising connection is explained easily when we understand that a lot of sh- and si- and related sounds in Latin turned into j- in Spanish. Thus, the b‑s maps to b‑j almost exactly.
The “sh” sound — often represented in writing as an “x” — transformed in all different ways to the “j” letter (and the accompanying mouth-clearing sound, influenced by Arabic) as late Latin turned into Spanish. See lots of examples: sherry/jerez, for example.
Here’s another: the common Spanish word, dejar, meaning, “to leave to the side” or “to put down” or to “put away” or to just “let go.”
Dejare comes from the Latin laxare, meaning, “to loosen”. From this same root, we get a few English words — which did not go through the x‑to‑j transformation Spanish did including: