"something deep down" is a grammatically correct phrase that can be used in written English.
It is typically used to describe a feeling or thought that someone has that is hidden or not easily expressed outwardly. Example: "Despite her outward confidence, there was always something deep down that made her doubt her abilities."
"It's hard to explain but there's a way of life, something deep down, that makes it difficult to fulfil its potential.
It may not make any personal sense, but something deep down in our DNA makes us retreat into the sovereignty of the tribe, even though its leaders conduct affairs like a pantomime.
Not just for reasons of "open" justice, but also for something deep down within me that requires "a pound of flesh", I find I could never advocate a guilty sex offender having anonymity for life.
Something deep down said it was the right choice for me.
Don't try to force yourself to be something deep down inside that you're not.
"I made aliyah, I moved to Israel, because of something deep down I didn't quite understand," Mrs. Kitay said.
But at Mr. Merckle's memorial service, Gerhard Maier, a retired Protestant bishop, said, "What brought a man of great will who felt responsible to God to the point where he took his own life is something that, deep down, we humans will never comprehend".
From Palestine to Jordan, Iraq to Syria, Lebanon to Kuwait, they're a well-travelled bunch, but as Mohammad says "until that right of return is rectified, I think all Palestinians - even though we've spread all over the world and found new homes - we'll always have something missing deep down".
When fathers and mothers go to look for their children something changes deep down in their own relationship.
The son of a preacher, he drew on his religious upbringing for uplifting messages: "I like to think of advertising as something big, something splendid, something which goes deep down into an institution and gets hold of the soul of it.... Institutions have souls, just as men and nations have souls," he told GM president Pierre du Pont.
Something was wrong, deep down, but I didn't know what it was or how to fix it.
