How would you explain “twix” in the context?
His penmanship was fair to good, and I was no stranger to his hand. I believe these texts to be loyal and stanch to his, apart from some small favors to a boy’s spelling and grammars. And small is the need, for a boy that took his lessons from The Mysterious Affair at Styles and so forth. I took some reliable help with translating the Spanish, which he used now and again, probably without full understanding of the difference when young. He spoke both languages as a routine. English with the mother, Spanish with most others until his return to the United States. But sometimes he twixed the two, and I’ve had to guess on some.
PS: “I” in the context refers to an archivist who kept the other’s diaries.
How would you explain “twix” in the last sentence? Does it mean he made the mixture of the two languages?
Thanks!