I got a partial refund in 2017. How do I see if the rest was accounted for in 2018?

Go to this IRS website for federal tax refund FAQ's - https://www.irs.gov/refunds/tax-season-refund-frequently-asked-questions

Why is my refund different than the amount on the tax return I filed?
All or part of your refund may have been used (offset) to pay off past-due federal tax, state income tax, state unemployment compensation debts, child support, spousal support, or other federal nontax debts, such as student loans. To find out if you may have an offset or if you have questions about an offset, contact the agency to which you owe the debt.

We also may have changed your refund amount because we made changes to your tax return. You’ll get a notice explaining the changes. Where’s My Refund? will reflect the reasons for the refund offset when it relates to a change in your tax return.

Tax Topic 203 - Refund Offsets for Unpaid Child Support, Certain Federal and State Debts, and Unemployment Compensation Debts has more information about refund offsets.

Call the IRS: 1-800-829-1040 hours 7 AM - 7 PM local time Monday-Friday
When calling the IRS do NOT choose the first option re: "Refund", or it will send you to an automated phone line.
So after first choosing your language, then do NOT choose Option 1 (refund info). Choose option 2 for "personal income tax" instead.
Then press 1 for "form, tax history, or payment".
Then press 3 "for all other questions."
Then press 2 "for all other questions."
- When it asks you to enter your SSN or EIN to access your account information, don't enter anything.
- After it asks twice, you will get another menu.

Press 2 for personal or individual tax questions.
Then press 4 for all other inquiries
It should then transfer you to an agent.

No one else can see your account or your tax returns.  You say you received a "partial refund" in 2017.  We do not know what you mean by that, nor can we look at any of your records to see.  Was some of your income tax refund offset to pay back taxes, child support, or student loan debt?  TurboTax never knows about offsets to your refund.  When your refund is taken to pay a debt you owe, you get a letter from the IRS or state that explains why they took your refund.

Or....did you not receive either a federal or state refund for that tax year?  Each tax year is separate--so we cannot know why you think the "rest" would be accounted for in 2018.

We cannot help unless you provide some details.  And of course---this is now 2020--why have you waited so long to ask?