"contribute a substantial" is correct and usable in written English.
You can use it when you want to say someone gave or donated a lot or a large amount of something. For example: "The family contributed a substantial amount of money to the charity."
Mr. Maazel believes in his work enough to contribute a substantial amount of his own money to support it.
If a relative (non-nuclear family) will contribute a substantial amount toward tuition, is that accounted for on the Fafsa?
"At the current stage of development that Bangladesh is in, children contribute a substantial percentage of income of poor families," McGrath said.
French officials say that they will probably contribute a substantial number but do not plan a formal announcement until the NATO summit meeting next month in Bucharest, Romania.
I have thought about a system in which each team had to contribute a substantial amount of money to a central pot.
Thick films, therefore, may contribute a substantial proportion of moisture in sandy loam soil over agronomically relevant matric potentials and timescales.
"Southern Cross Austereo has contributed a substantial amount to a trust which was recently established to assist Ms Saldanha's family.
Industry accounts for only a quarter of the country's gross domestic product but contributes a substantial part of the government's revenues.
But within 48 hours, Lord Lloyd-Webber contributed a substantial share of the $800,000 that had been withdrawn from the show, and four others joined him in the bailout.
Even in extracts from wild-type mice, mSMUG1 contributed a substantial fraction of the total UDG-activity under these assay conditions.
Once, they mobilized their Manhattan neighbors, raising funds and contributing a substantial share for the planting and care of trees on their street.
