Legal Question in Landlord & Tenant Law in Illinois

Without seeing the lease and asking some additional questions, it would be irresponsible to advise you. But here are some basics to consider:

1. "Breaking" a lease means breaching it -- opens you up to a breach of contract lawsuit.

2. April v. June. If the lease term said April and you weren't able to move in for 2 months, maybe (MAYBE) the landlord breached the lease but if your ex moved in that may have cured the breach.

3. You signed what may be a binding legal agreement. You may be jointly and severally liable. Your ex may be legally responsible to try to "mitigate" his damages by finding another "roommate" to share expenses with, IF the landlord will allow it. If your ex sues you, he may or may not be able to get his attorney fees and costs paid for too.

4. You may want to talk to the landlord because you may have the right to sublease or assign your position.

5. Depending on how much 50% of the total year's rent is, you may want to consider taking the lease to a local lawyer to review even if the review costs you something. You can also consider settling with your ex.