Alex, who built that tower, was an engineer. You need commas.
Alex, who was an engineer, built that tower. You need commas. Alex was the engineer who built that tower. No commas here. (because you're specific which engineer you're talking about, I think you s
To go off the point slightly, be careful about the difference between 'true' and 'correct'. I know some languages have one word that covers both meanings but in English they are different. You should have used 'correct' in your comment.
For example, to say that 'The sea is orange' is grammatically correct, but it is not true. 'The sea are blue' expresses an idea that is 'true' but it is n
Alex, who built that tower, was an engineer. You need commas.
Alex, who was an engineer, built that tower. You need commas.
Do you really need commas here? I mean, those sentences can be both defining and non-defining. If they are defining, so e.g. in the first sentence you define which Alex was an engineer, you dont use
<Do you really need commas here? I mean, those sentences can be both defining and non-defining. If they are defining, so e.g. in the first sentence you define which Alex was an engineer, you dont use commas. And if its non-defining, u have to use commas.>