-(e)la

In English, "that" is a separate word at the start of the clause. In Basque, the marker is an ending on the conjugated verb, which normally comes at the end of the clause.

How to form it. Add -ela to the auxiliary or one-word verb. A few sound changes happen:

• Most forms simply add -ela: du → duela, naiz → naizela, dago → dagoela, daki → dakiela.
• A final -a changes to -e: da → dela, zara → zarela, dira → direla.
• A final -t changes to -d: dut → dudala, ditut → ditudala.
• A final -r doubles: dator → datorrela.
• Past forms drop their final -n: zen → zela, zuen → zuela.

Verbs that take a -la clause include esan (say), uste izan (think, believe), jakin (know), entzun (hear) and pentsatu (think). The -la clause can come before or after the main verb: Uste dut etorriko dela and Etorriko dela uste dut both mean "I think she will come."

Only the ending changes. The inner sentence keeps its own word order, with the verb last: Hemen bizi zara → Badakit hemen bizi zarela.

Negative sentences. A negative inner clause becomes ez dela, ez duela and so on: Uste dut ez dela etorriko (I think she won't come). See negation inside a clause. When the main verb itself is negative, careful Basque often uses -(e)nik instead: Ez dut uste etorriko denik.

Not for describing nouns. To say "the book that I bought", Basque uses a different ending, the relative -(e)n: erosi dudan liburua. In this entry, -la reports what someone says, thinks or knows.