Embassy (and Ambassador) and its Spanish equivalent, Embajada (and Embajador), both come from the same ancestor, the Old French Ambactos.
What is most interesting about these two is that it is an example of the pattern where the ‑j- sound in Spanish maps to the ‑sh- sound (and its cousins, like ‑ss- and ‑ch-) in English. Remember syrup and jarabe, chess and ajedrez, sherry and jerez, and push and empujar for a few examples.
Thus, the m‑b-j of emabajada maps to the m‑b-ss of embassy.
The Spanish “Huir” comes from the same Latin root as “fugitive”, “fugitivus”, meaning, “to flee”.
Pattern: Latin words that began with an ‘F’ tended to lose that initial ‘F’ sound and became silent (yet represented in writing with an ‘H’) as vulgar Latin turned into Spanish.
The Spanish caja (“box”) comes from the Latin capsa for the same.
This gives us a surprising connection to some English words that, on the surface, sound very different than caja:
The Latin turned into the Spanish through an interesting pattern: the ‑sh- sound in Latin consistently turned into the ‑j- sound in Spanish (at first retaining the original pronunciation, but then under the influence of Arabic, grew to the throat-clearing sound). With caja, we have a slight variation of the pattern, where the ‑ps- sound turned into the ‑j- sound. Thus, the c‑ps maps exactly to c‑j.
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!
It is both surprising and funny that in Spanish, a Flea Market is translated to be, literally, exactly the same: Mercado de Pulgas.
But it is even more surprising (although probably less funny) that flea and its Spanish translation, pulga, are close cousins — despite the different sounds.
Both derive from the Indo-European *plou. To understand this transformation, we should remember that the Indo-European p- sounds stayed the same in Latin (and thus Spanish) but became an f- sound in German (and thus English).
Therefore, the f‑l of flea maps exactly to the p‑l of pulga!