I run El Capitan but had the same problem with prior operating systems. I can't use the single quote key to type a straight quote mark in the apps that I want, in particular an abc notation app called EasyABC. Having just stated that I notice the word can't does that a straight quote!!! In EasyABC there is no Substitutions menu so I don't know what to do.

Dani AI

Generated

Short summary for (and building on ): the behavior is macOS automatic “smart quotes” converting the ASCII apostrophe into typographic quotes. That substitution can be turned off per app (when the app uses the macOS text system) or turned off system-wide. The easiest diagnostic is to type the same character into a Cocoa app like TextEdit — if it becomes curly there too, the system setting is in play; if it does not, the problem is app-specific.

Turn it off (per-app or system)

  • Per-app: look in the app menu Edit > Substitutions (or Edit > Substitutions > Show Substitutions) and uncheck Smart Quotes when that menu is available.
  • System-wide: open System Preferences (Keyboard) -> Text and disable “Use smart quotes and dashes”. This is the documented place for text substitutions and smart quotes on macOS. (support.apple.com)
    Apple Support: Replace text and punctuation in documents on Mac

Force-disable from Terminal
If an app has no Substitutions menu (or the global checkbox doesn’t help), disable the OS feature from Terminal with these commands, then quit and relaunch affected apps (or log out/login) so they pick up the change:

defaults write -g NSAutomaticQuoteSubstitutionEnabled -bool false
defaults write -g NSAutomaticDashSubstitutionEnabled -bool false

These preference keys are commonly used to disable smart quotes/dashes system-wide. (apple.stackexchange.com)
(See the Ask Different discussion for examples and per-app variations.)

If the app still converts quotes
EasyABC is an open-source wxPython/wxWidgets app rather than a pure Cocoa text app, so it may implement its own text handling or inherit behavior that ignores macOS substitutions. If disabling the system keys above has no effect, try typing in a plain Cocoa editor and pasting into EasyABC, test a newer EasyABC build, or report the issue to the EasyABC project. (github.com)

Quick one-off: immediately press Command-Z after the automatic replacement to revert it back to a straight quote (useful when only an occasional straight quote is needed). (macworks360.com)

References: Apple support page above; Ask Different (defaults keys); EasyABC project page; MacWorks360 tip about Command-Z. (support.apple.com)

I'm going to write your El Capitan is not a typewriter. Read http://practicaltypography.com/straight-and-curly-quotes.html to learn how to turn on/off smart quotes in Word and ask the EasyABC support/author if they support this.

I'll disagree about Word and straight quotes.

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.