The phrase "a straightforward expression" is correct and usable in written English.
You can use it to describe a phrase or statement that is clear and easy to understand.
Example: "The author used a straightforward expression to convey complex ideas in a simple manner."
Alternatives: "a clear statement" or "an uncomplicated phrase".
The song seems like a straightforward expression of thanks to the band's fans, though it sounds like something much stranger.
These subtleties have largely been lost through the work's mass reproduction and Flag is now displayed, more often than not, as a straightforward expression of patriotism.
When the artist showed his first encaustic flag at Leo Castelli, in 1957, it was hardly considered a straightforward expression of patriotism.
This is a moderate attitude, but also a straightforward expression that was rarely seen in the media previously.
It's rare to see such a straightforward expression of how confusing it is to leave childhood behind and develop into a sexual adult within the family unit.
In part, as the pioneer student of this phenomenon, Ross Gelbspan, has demonstrated, it is a straightforward expression of the material interests that are threatened the fossil fuel corporations and their business allies.
This appears to be an entirely straightforward expression of a theory of divine illumination.
"Leaving California" is a more straightforward expression of displacement, but elsewhere the concerns are barely worth bothering with.
But writing in a non-fictional mode, as in the essays of Known and Strange Things, permits me a more straightforward expression of what's at stake – and part of what's at stake is getting to the point where we say, "Come the fuck on, this should all be self-evident by now".
I mean, hearing the truth from someone's lips can be quite attractive, especially when it's a pure, straightforward expression from one person's heart and soul to another.
A recent review into the approach that was developed by Matthes and Haas has determined that a straightforward analytical expression can be derived for the doubles correction that is similar to the singles rate correction that was developed in their original work.
