When only six or seven years of age, he was discovered on the roof of the barn, much to the consternation of his father and mother, fixing up a windmill of his own construction.
When only four or five years of age, he was often seen dividing circles and squares.
The surveys of numerous collieries which he was called upon to make, gave him further experience; and already, when only twenty-three years of age, he contemplated making a model of the strata of the earth.
In 1809 Byron, when only twenty-one years of age, started on a tour of Europe and the Orient.
He died miserably in 1796, when only thirty-seven years old.
When only ten he wrote 'The Tragical History of Pyramus and Thisbe,' and at twelve 'Constantia and Philetus.
When only twenty, he lost his father in remarkable circumstances.
He was very early distinguished as a prodigy of boyish acquirement, and was entered, when only eleven, of Harthall, now Hertford College.
When only twenty-two he was already a master-painter in the Antwerp Guild.
A lad of so much enterprise was evidently designed to make some figure in the world, and we accordingly find him, when only twenty-six years old, contesting the county in 1784.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "when only" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.